ALBERT

Description: The heavy yields of sugar beet tops which remain on the land after the removal of the sugar beet crop may be utilised in two ways. They may either be ploughed into the land as manure, or they may be fed to stock. Where large areas of sugar beet are grown, and where in consequence it may not be possible to secure consumption of the whole of the tops before decomposition of the material sets in, a combination of these two methods of utilisation may be resorted to. In other words, the feeding of the tops may be continued so long as they remain wholesome, after which the remainder may be ploughed into the land.In view of the present importance of the sugar beet crop in English agriculture, and the urgent necessity of making the fullest possible use of all the various by-products arising in connection with this crop both in the field and in the factory, it is of importance that data should be available relating to the value of sugar beet tops both as a feeding stuff and as a manure. The purpose of the present communication is to detail the results of investigations which have been carried out with a view to securing such information.

Description: The practice of applying nitrogenous fertilisers to cereal crops as a top dressing is one which has become firmly incorporated into normal farm routine.The classic wheat experiment on Broadbalk field shows that to apply all the nitrogenous fertiliser at the time of drilling the seed in autumn leads to a diminution in crop when compared with the yield of a plot in which only a quarter of the nitrogenous fertiliser was applied in autumn.

Description: It has been shown that dried sugar-beet pulp contains a high percentage of pectose. A number of successive digestions of 1 hour each with 0·5 per cent. ammonium oxalate at 100° C. extracts an amount of pectin equal to 34·5 per cent. of the weight of dried beet pulp, basing the determination on the weight of crude pectin precipitated when the extracts are run into 95 per cent. alcohol. A single prolonged digestion gives a yield of crude pectin equal to 32·2 per cent. of the dried beet pulp.Digestion with acidic reagents, such as 0·5 per cent. oxalic acid, 0·6 per cent. tartaric acid, N/20 hydrochloric acid, etc., leads to a quicker extraction of pectin, owing to a speeding up of the pectose to pectin hydrolysis. The yield of pectin, however, is not thereby necessarily enhanced, since under such conditions the pectin undergoes a slow secondary hydrolysis during the extraction with the formation of reducing substances not precipitated by alcohol.Prolonged digestion at 100· C. of dried sugar-beet pulp with water alone also leads to a satisfactory extraction of pectin.

Description: (1) The desiderata of a sampling-method are outlined, and the particular case of sampling a large number of potato plots discussed.(2) An analysis is made of the yields of 54 sub-plots of the Rothamsted Potato Experiment of 1928, both as estimated by a sampling-method and as determined by large-scale lifting.(3) It is shown that most of the significant results of the experiment are obtained from the sample-yields, but that the higher standard error per plot obscures the effect of superphosphate.(4) It is concluded that at Rothamsted 102, and at Woburn 56, plants would have to be lifted to give a sampling-error as small as 4 per cent. It would then be profitable only to sample experimental plots of 1/20th acre or more in area.Finally it is a pleasure to record our indebtedness to Dr R. A. Fisher for much valuable advice and criticism: and to Mr H. J. G. Hines for assistance with the field work.

Description: The last issue of this Journal (p. 132) contains a paper by Dr R. A. Fisher on the effect of Silica upon the growth of Barley at Rothamsted, which begins by stating that his data “show conclusively that the view previously rejected that the silicate acts by making available to the plant the actual reserves of soil phosphates must be regarded as strongly established.” Twice elsewhere Dr Fisher states that this erroneous conclusion of previous investigators is due to the fact that they had considered only the proportion of phosphoric acid in the ash and had overlooked the increase in the total phosphoric acid in the crop. As Mr Morison and I were the previous investigators in question I turned to our twenty-three-year-old paper with some curiosity to ascertain the grounds for this magisterial dismissal of our conclusions, for my remembrance of the subject did not tally with the opinion Dr Fisher attributes to us. Still less do I agree now that I have re-examined our original paper.

Description: The determination of dissolved oxygen by Thresh's method may lead to discordant results because of the loss of iodine, which is carried away by the gas passed through the apparatus during the titration.A modified method is described, which eliminates the above error and obviates the necessity for making separate determinations of the dissolved oxygen of the reagents used.Correction for the nitrites present in the water can be made by making separate determination by the Griess-Ilosway colorimetric method.

Description: 1. The various classes of insecticides are outlined, and the sense in which the term “contact insecticide” is used is denned as one which is brought into external contact with the insect, either as solid, liquid or vapour.2. An analysis is made of the relationships between chemical constitution and insecticidal action in the vapour phase. There is rough correlation between both the molecular weights and volatilities of organic compounds and toxicity, but it is probable that these relationships are only indirectly involved and that they indicate a connection of a more direct kind with some other property such as adsorption.3. An account is given of the toxicity to insects of certain plant products. The most potent of these are certain tropical leguminous plants used as fish-poisons. A brief account is given of the chemical derivatives found in these plants. One of them, “tubatoxin,” is one of the most potent contact insecticides known.4. A list of the groups of organic chemicals tested for their toxic action on Aphis rumicis and the eggs of Selenia tetralunaria is given. A more detailed account is given for each group of the relationships between chemical constitution and insecticidal action. It is shown that the substitution of certain radicals in the benzene ring profoundly affects toxicity, but that toxic action depends not only upon the radicals but the number substituted and in certain cases upon their relative position.5. 3 : 5-Dinitro-o-cresol is shown to have a most powerful ovicidal effect.6. An examination of the toxicity of the fatty acids is made. It is shown that as the series is ascended toxicity increases up to undecylic acid, after which it declines.

Description: 1. The toxicity of 3:5-dinitro-o-cresol and its sodium salt to the eggs of several species of moths has been determined under laboratory conditions. Both substances are toxic to eggs of the species tested at concentrations varying from 0·1 to 0·025 per cent.2. With eggs of some insects, hatching is not entirely prevented by the action of low concentrations of dinitro-cresol and sodium dinitrocresylate, but the majority of the larvae which emerge succumb within a few hours.3. The eggs of “red spider” are very resistant to the action of dinitrocresol.4. At equivalent concentrations, dinitro-cresol and sodium dinitro-cresylate have approximately the same toxicity to insect eggs.5. Washing eggs with water after spraying has no appreciable effect on the toxicity of dinitro-cresol, if the liquid is first allowed to dry on the eggs. Sodium dinitro-cresylate is more affected by washing after spraying.6. Field experiments on apples and black currants with spray fluids containing dinitro-cresol at a concentration of 0·25 per cent. and sodium dinitro-cresylate at equivalent concentration showed that both materials were completely effective against Psylla and Aphis eggs and greatly reduced the numbers of caterpillars. There was no evidence of any effect on Capsid eggs.7. Both fluids had a cleansing effect on the bark of the trees, killing algae, lichens, etc.; they caused no injury to the trees themselves. The results demonstrate the practicability of using dinitro-cresol and sodium dinitro-cresylate as winter spray fluids on dormant trees and bushes under field conditions.

Description: (1) An aerobic coccus has been obtained from cultures of the motile butyric acid bacillus under conditions which exclude the possibility of contamination.(2) Descriptions of the coccus and the bacillus are given.(3) The coccus does not fix nitrogen in soil extract containing dextrose.

Description: The mechanism by which viscogen (calcium saccharate) brings about an increase in the viscosities of milk and cream has been investigated.The primary reaction appears to be the formation of a precipitate of insoluble (tri-calcium) phosphate. Considerable quantities of casein are carried down by the precipitate, and this co-precipitation of casein is probably the single factor which most influences the viscosity.Casein is not directly precipitated by viscogen, but the viscosity of its solutions is slightly increased as a result of their higher alkalinity due to this reagent. This action of viscogen is relatively unimportant in influencing the viscosity of milk or cream.

Description: 1. Two basic slags differing widely in solubility and phosphate content have been treated for long periods with boiling ammonium chloride solution.2. The low-grade slag lost 70 per cent. of the total lime and very little phosphoric acid; a residue with nearly 40 per cent. phosphate was obtained from an 18 per cent. slag.3. The high-soluble slag also lost a large percentage of the total lime but large amounts of phosphoric acid were also found in solution. The residue from the 30 per cent. slag after 24 hours' treatment contained nearly 46 per cent. phosphate.4. It is shown that a silico-phosphate is present in the high-soluble slag, but not in the low-grade slag.5. The solubility in citric acid of the phosphates in the various residues has been determined.6. The value of basic slags in supplying exchangeable calcium is discussed.7. The effect of hydrofluoric acid on the slag residues has been investigated.8. Experiments with fluorspar slags are described which confirm the view that the phosphate present is fluorapatite of very low solubility in citric acid.

Description: Some of the factors affecting the rate of loss of water from a drying system are shortly reviewed. These factors fall into two groups: (1) the drying system itself, and (2) the environmental conditions. The second group may include (a) diffusion of water vapour through the air, (b) bulk air movements due to (i) temperature gradients between different parts of the drying vessel, (ii) temperature lowering of the drying mass itself due to evaporation, (iii) lower density of moist air, (iv) inevitable disturbances introduced by experimental conditions such as weighing or movement of apparatus, (v) the geometry of the system. It is shown that of the external factors the most important are (2 (a)), (2 (b) (i)) and (2 (b) (ii)); (2 (b) (iv)) may produce irregularities in the rate curves of airdry granular materials; (2 (b) (iii)) and (2 (b) (v)) appear to have little or no effect.

Description: Herd statistics of cattle in India suggest that for animals of about 3500 lb. yield capacity a calving interval of rather less than a year will give the best results in the following lactation. For cattle whose yield capacity is 6000 lb. an interval of 420 days is desirable while one of less than 335 days is seriously injurious.Study of individual cows and their recorded histories reinforces the above conclusions and also suggests that the interval should be longer in early lactations than in late and progressively longer as the milking capacity increases.It also indicates that unrestricted access to the bull may prevent the real yield capacity of a cow being discovered.

Description: 1. In pot experiments with Glycine hispida and Vicia faba L., fresh chaff incorporated with the soil caused a significant increase in the number of nodules produced on inoculated plants, this increase being augmented by the further addition of phosphates.2. Fresh chaff, added at the time of sowing and inoculation, had more effect than chaff which was allowed to decompose in the soil for a month.3. Fresh chaff increases the multiplication of the nodule organism in sterilised soil.4. In soy beans without nodules, the chaff depressed the growth of the tops, but this depression did not occur either with soy or broad beans where nodules were present.5. In a field experiment made at Rothamsted, chaff, freshly ploughed in, increased the growth of broad beans and also of wheat sown the next season on the same ground.

Description: In the first paper of this series (10)1, Keen and the present writer discussed work by earlier authors on the approximate specification of the nature of a soil by a single soil constant, in place of a detailed analysis, and described experimental work designed to show the significance of a number of simple physical measurements. The chief objects of the present paper are to describe the results obtained with such measurements as applied to a number of Natal soils, and to discuss the value of some other easily obtained physical data as a means of specifying the nature of a soil. Work of this type was discussed at the International Congress of Soil Science at Washington in 1927, and it was resolved that co-operative work on an international basis should be undertaken.

Description: 1. Cereal plots were sampled by three different methods; two systematic, and one involving a random location of sampling units.2. The disadvantages of the systematic methods as compared with random sampling, emerged clearly.3. These disadvantages were further emphasised in an analysis of earlier data on sampling methods. For this purpose the methods and. results of certain recent contributions to statistical theory were used.4. By the use of a random sampling method, the variance due to sampling errors may be made a satisfactorily small fraction of the total variance of cereal plots one-fortieth of an acre in area.

Description: 1. The nature of the replaceable base in a clay or soil exerts a profound effect on the physical properties. Clay-like properties are exhibited most strongly in the case of lithium, sodium, and magnesium.2. The proportion of fine material in a soil (i.e. that which remains in suspension in a column 10 cm. high after 14 days) cannot be correlated with other physical properties. Thus a soil of which over 50 per cent, was dispersed to this extent was the least plastic of those examined.3. A comparison of sodium, potassium, and calcium clays and soil showed that potassium resembles sodium in its chemical relationships as indicated by base exchange, but is very different from it in such physical properties as plasticity and permeability.4. Using mixtures of one-half normal chlorides of two bases, calcium and potassium are absorbed in equivalent amount while the sodium absorbed is only one-sixth of the amount of either of the other two.

Description: The cobaltinitrite method, in the volumetric form here described in detail, enables known amounts of potassium to be accounted for quantitatively, independently of the presence of alkaline earth sulphates, or phosphates, provided that the amount of potassium is not varied over too great a range. The factor 0·000830 gm. K2O per c.c. N/10 KMnO4 suits the procedure described over a range of about 3 to 50 mg. K2O. Outside this range, or for highly accurate work within it, it may be desirable to calibrate the method.The method may be applied, in plant-ash analyses, indifferently to the original extracts containing other bases and phosphates, or to the mixed sulphates weighed for sodium and potassium together. It is applicable to small-quantity work upon soils with greater exactness and speed than is the perchlorate method. Citric acid extracts can be handled, with a relatively short manipulation, to give satisfactory results.Some analyses of ammonium chloride extracts have been unsatisfactory, and attention is called to the desirability of setting exchangeable potassium determinations upon a firmer analytical basis, by investigation of methods of freeing the extracts from ammonium salts.

Description: Though it is neither customary nor perhaps desirable to utilise sugar beet for feeding purposes, it is conceivable that circumstances might arise occasionally when a farmer would be desirous of feeding the whole or part of his beet crop. This is indicated by the fact that enquiries as to the value of sugar beet for pigs are received from time to time. During the carrying out of the investigation into the value for pigs of dried sugar-beet pulp and molasses-sugar beet pulp, an account of which work is given in this issue of the Journal (1), the opportunity was taken of making a similar study of whole sugar beet. A dual investigation was made, consisting of a digestion trial under the conditions of the metabolism room and a large-scale feeding trial under ordinary farm conditions. It was hoped that the evidence from this twofold line of enquiry would not only settle the question of the value of sugar beet in the feeding of pigs, but also throw light on the subject of the value of root crops in general for swine.

Description: The severe climatic conditions under which cotton is grown in the Gezira make it desirable to establish relations between meteorological data and irrigation practice. By means of a rapid and fairly accurate balance it is practicable to measure water loss when small boxes containing moist soil are exposed for short periods and under different conditions. The scope of this method has been ascertained by preliminary experiments as to (1) the dependence of water loss on moisture content of the soil, (2) the distribution of water loss through the day, (3) the comparison of water loss from sand and from. Gezira soil, and (4) the comparison of water loss from shaded and unshaded soil. The application of data so obtained to field problems is facilitated by the fact that in respect to distribution and amount losses from soil are related to loss shown by a Piché evaporimeter. Within the canalised area alternation of irrigated and fallow land is responsible for local variations in atmospheric conditions. A daily fluctuation in the moisture content of surface soil from fallow land is recorded and may be instrumental in favourably modifying its physical properties. The heat of wetting of Gezira soil has been measured.

Description: (1) The mineralogical composition of the fine sand fraction of certain soils from the south-east of Scotland is described.(2) The soils are shown to possess a fairly high content of silicate minerals in a comparatively fresh state.(3) The distribution and amount of potash, phosphate and lime-bearing minerals in the soils is discussed.(4) The soils can be grouped according to their mineral content and this grouping is found to depend on the geology of the parent material.(5) All the soils are formed on glacial drift and the results suggest that the local rocks have a preponderating influence on the composition of the matrix of the drift.

Description: (1) In absence of decomposing organic matter addition of nitrate led to no loss of nitrogen.(2) On addition of small quantities of fermentable matter such as glucose there was (a) rapid depletion of nitrates and oxygen, but no denitrification, and (b) increase in acidity, carbon dioxide and bacteria. The greater part of the soluble nitrogen was assimilated by microorganisms or otherwise converted and the greater part of the added carbohydrate was transformed into lactic, acetic and butyric acids.(3) The organic acids were formed from a variety of carbohydrates. Lactic acid was the first to be observed and appeared to be formed mainly by direct splitting of the sugar. It decomposed readily, forming acetic and butyric acids. Some acetic acid was formed by direct oxidation of lactic acid, with pyruvic acid as the intermediate product. All the acids were, on standing, converted into other forms by micro-organisms.

Description: (1) Soil surveys are classified into (i) preliminary reconnaissance surveys, (ii) broad ecological surveys, (iii) detailed physiological-ecological surveys, and (iv) special-purposes surveys. The objects of each are briefly discussed.(2) Particular consideration is given to the methods of physiological ecology, which attempt to assess the chief soil factors controlling plant growth.(3) Soil factors are grouped into (A) static factors, which do not fluctuate appreciably during a growing season, and (B) dynamic factors that may exhibit marked fluctuations within a season, or during years when climatic conditions vary.

Description: The conclusions of the 1927 experiments in spacing have been tested in greater detail in 1928 and are confirmed.From the 64-plot scheme containing a series of spacings in quadruplicate the following points emerged:(1) Variation of the width between the rows influenced the yields of sugar beet roots, the expectation of highest yield being on the narrowest spacings. There was a significant increase in yield to be gained by using 15” or 18” spacing instead of 21” or 24”. On the other hand width between the rows did not seem to influence the yield of tops and crowns.(2) Variation of the distance between plants in the rows up to 10” had no significant effect on the yield of roots. There was some evidence that above that figure a reduction in yield took place. It is interesting to note that in the case of the tops, spacing between the plants influenced the tonnage. There was a significant difference between the yields on the 4″ and 8″, and 4″ and 10″, but not between the 4″ and 6″, 6″ and 8″ or 8″ and 10″ spacings.

Description: The results of an investigation into the utilisation of sugar-beet pulp by ruminant animals were brought forward in a recent publication (I). It was demonstrated that sugar-beet pulp is highly digestible when consumed by ruminants. In respect of the digestibility of its N-free extractives and total organic matter, it compares very satisfactorily with maize meal. The process of drying the wet beet pulp in the factory does not depress its digestibility. Further, from the standpoint of digestibility, it is immaterial whether sugar-beet pulp is included in the rations of ruminants in the dry or the soaked condition. When, however, liberal allowances of the dried product are being fed to animals, it is desirable that the food should be well softened in water before feeding. This procedure ensures a higher availability of the digestible nutrients for productive purposes in the animal and also averts risk of choking trouble which sometimes arises, especially with sheep and lambs, during consumption of the dried beet pulp.

Description: Very considerable amounts of money are annually expended in Mauritius for the purchase of artificial fertilisers, and consequently it is of importance to know what happens to these substances when they are added to the soil. Extensive laboratory experiments have been carried out with nitrogenous fertilisers(1, 2), and also with phosphatic manures(3), and in order to complete the series an investigation into the availability of potash when applied in various forms was undertaken. Local practice favours the use of potash chiefly in the form of nitrate of potash and molasses, and on this account the availability of the potassium oxide in these two substances was tested, and in addition, in potassium sulphate.

Description: (1) A large series of data on the duration of gestation in the goat has been analysed and the constants calculated.(2) The frequency curve is unimodal and symmetrical, suggesting a single factor or a variety of factors acting simultaneously as the cause for birth.(3) Slight breed differences exist in the duration of gestation in the goat as in other species examined.(4) There is a continuous variation in the duration of gestation with the time of year at which conception occurs. Spring conceptions give shorter gestations than autumn conceptions.(5) There is a distinct difference in the duration of gestation for young and older dams. This is related to the age of the dams and not to the order of the births. Gestation is shorter in the young animal than in the older.(6) In the goat the size of litter has little or no effect on the duration of gestation.(7) Constants for duration of gestation in other species have been obtained. Variability increases with the duration of oestrus and about half the variability in any species with a long oestrous period may be ascribed to this cause.(8) The factors involved in fixing the duration of gestation in the species examined are evidently the same in all cases, and probably culminate in a single agency responsible for terminating gestation.

Description: 1. Percentages of fat, solids not fat and protein were determined in over 700 samples of mixed milk from 15 herds during 1925–26. In the case of fat content, nine herds produced one or more samples below 3 per cent., one herd recording 25 per cent, of samples below this limit. With regard to solids not fat, twelve herds produced milk containing less than 8·5 per cent, on one or more occasions, the highest percentage of deficient samples recorded being 40.2. Frequency distributions of fat, solids not fat and protein percentages in the samples analysed, are given, together with standard deviations, and mean percentages with probable errors for these three constituents.3. Correlation tables of fat with solids not fat, and protein with solids not fat have been prepared, and graphs illustrating the variations are given.

Description: (1) The ammonia formed in water-logged soils was present mostly in the soil sediment. The surface water contained only a very small portion of the total amount produced.(2) Added ammonia was in a similar manner retained mostly in the soil itself. It could not be leached out by extraction with water nor volatilised with increase of temperature. There is evidence to show that the ammonia exists in the soil as an exchangeable base.(3) On allowing the soils to dry out the ammonia disappeared rapidly and corresponding amounts of nitrates were formed. Very little ammonia was lost by volatilisation.(4) The production of ammonia took place even in presence of volatile antiseptics. The reaction was shown to be brought about by a deaminase.(5) Studies with a number of proteins and ammo acids showed that only very simple amino compounds (glycine aspartic acid and asparagine) were deaminised. Witte's peptone, which contains amino acids, was also attacked.(6) An active preparation of enzyme was extracted from the soil with an aqueous solution of glycerin saturated with toluene.(7) Significant deaminising action was shown by the enzymes from cultures of the mixed microflora of the soils.(8) By acting on amino bodies that are otherwise resistant to biological action the deaminase probably helps to release readily available plant food. Its action should be of great importance in tropical swamp soils.

Description: All Cows. It is proposed, in dealing with this question, to follow the same lines as in the previous Part—namely, to describe the effect as found from all the Norfolk records (comparing the results, where possible, with those found in the case of Penrith) and then to treat the various breeds, and high and low yielders separately, in order to bring out any peculiarities that may exist as regards those groups.It has already been seen that, as would be expected, the length of the S.P. very largely influences the length of the lactation, and it would seem probable on the face of it, that as pregnancy progresses the milk flow declines; this latter is dealt with in Section B of this Part, but we are here concerned with the total effect of both of these on the yield of milk in the lactation.

Description: 1. As a result of soaking in water at body temperature (38° C), foods show variations in swelling ranging from approximately 10 per cent. to 260 per cent.2. The volumes of equal weights of different foods after soaking also vary within wide limits. The percentages of moisture in the soaked foods show corresponding variations, being in some cases as high as those found in roots or green fodder.3. These facts have led the authors to put forward a new conception of “bulk” in assessing the value of a ration.4. Feeding experiments have been carried out to determine how far this factor of bulk is applicable in practice.5. In the case of pigs of 40 to 80 lb. live weight, the bulk occupied by the foods did affect the quantity of food taken.6. With calves, the swelling capacity of the concentrated food did not yield any definite results so far as food consumption was concerned.

Description: Although the primary object of recording cows' milk yields is to provide a means of comparing one individual with another, it is not satisfactorily achieved when the records have been obtained, since yields are influenced to a large extent by environmental factors which vary from cow to cow. The lactation record is the result of two sets of factors—genetic and environmental—and for purposes of selection and breeding it is important to be able to make accurate allowance for the one, so as to arrive at a good estimate of the other.Leaving aside the variation due to feeding and management (which, whilst undoubtedly large, is minimised for the cows of the same herd, and which it is hardly possible to study statistically in the existing data) the chief factors operating on the lactation yield (i.e. the measurable environmental factors) are the following:(1) Season of the year; the lactation yield is influenced to a certain extent by the month of the year in which the cow calves.(2) Service; i.e. the stage of the lactation at which the cow again becomes pregnant. The interval between calving and the next fertile service is here termed the Service Period (S.P.); thus if a cow calves on June 1st, and becomes pregnant again on July 1st, her S.P. for that lactation is 30 days.

Description: The theory of the capillary behaviour of moist soil has been further amplified for the ideal case and its relationship to various soil properties considered. Over part of the moisture range which has been dealt with by other authors it is found that there are alternative forms for the water distribution. This appears to explain why some differences of opinion have been expressed regarding some of the main points presented in a previous paper.The theory is considered in relation to capillary rise in soils as well as to the problem of cohesion previously dealt with. It is shown that the moisture distribution attained by capillary rise can be inferred from simple direct measurement of the suction pressure. Various other experimental illustrations of the theoretical conclusions are introduced.

Description: The investigation which has been dealt with in this communication was essentially a continuation of earlier work carried out in 1925 and was primarily designed with the object of ascertaining whether, under greatly differing conditions in respect of soil, herbage and weather, the striking results obtained in the 1925 investigation concerning the chemical composition, digestibility and nutritive value of pasture herbage, under a system of cutting resembling the conditions of close grazing, still held good.

Description: The laboratory study of the physical properties of soil and clays can conveniently be divided into three stages:(a) Moisture content comparable to that under field conditions.(b) Thick pastes.(c) Weak suspensions.The use of the plastometer for experimental work on intermediate stage is described and recent developments of the theory of the flow for thick pastes under stress are outlined. It is shown that certain constants defining the material can be obtained from the experimental data. The two to which special attention is given are the pseudo-viscosity (a quantity analogous to the viscosity of true fluids) and the static rigidity (which represents the energy required just to cause the paste to flow and a measure of the solid cohesive properties of the system). The latter quantity is related to other physical measurements made under very different experimental conditions, e.g. the resistance of the soil to the passage of cultivation implements; the effect of chalk, etc., on the soil resistance; the moisture content at which a well-kneaded mass of soil is about to become sticky.

Description: Methods for extraction, concentration and determination of minute quantities of soluble carbohydrates, lactic acid and volatile fatty acids have been described. Different factors affecting the accuracy of the determinations have been studied and corrections, where necessary, have been suggested.

Description: An account is given of observations made during the first two years' treatment of grass according to the “New System of Grassland Management,” i.e. periodic dressings of nitrogenous manure followed by rotational grazing.The grazing provided by the nitrogen and no-nitrogen plots in the two years is given, measured in cow-day equivalents.A method of sampling the plots with a view to determining the total weight of herbage produced and its chemical and botanical composition is described.Botanical and chemical results obtained by this method are given and discussed.The percentage of clover on the nitrogen plots is about one-quarter of that on the control plots.The dry matter of the herbage on the nitrogen plots has, on the average, contained 17·7 per cent, crude protein: that on the no-nitrogen plots 15·5 per cent. The average age of the grass when sampled was 35 days.

Description: This paper is a record of the composition of the milk of an abnormal cow, during a period extending over three lactations. Although this cow was found eventually to be suffering from tuberculosis of the udder and lungs, no signs of the disease were apparent during the first two lactations recorded.The milk produced by this cow was abnormal during the whole period under review. Fat percentages were very variable, but the solids not fat content was consistently low, only 2 per cent. of the total number of samples analysed exceeding 8·5 per cent. in this constituent. Protein and lactose percentages were much below the averages for normal milk, but in the case of total ash the mean figures were normal. Of the ash constituents, the soluble portion was very high and the insoluble portion correspondingly low, the former presumably indicating a high chloride content. The percentages of phosphoric acid and lime were considerably below the mean figures for normal milk.Lactose and soluble ash percentages show a marked negative correlation, and moreover support the contention of Porcher and others that a definite lactose-chlorine ratio exists in milk.It is suggested that an abnormally low solids not fat content (i.e. low protein and lactose) and abnormal percentages of the individual ash constituents may be a sign of incipient disease affecting the organs involved in the secretion of milk.

Description: (1) The solubility of the potash in 34 soil samples from 13 soils typical of large areas in the East of Scotland has been determined by the methods of chemical analysis using (a) hot concentrated hydrochloric acid, and (b) 1 per cent, citric acid solution, and the values obtained compared with the quantities of potash existing in the exchangeable form. The total mineral potash has been determined for six samples and Neubauer's method of analysis has been applied to 10 samples and again compared with the exchangeable potash.(2) The average value of the total mineral potash in the soils examined was 2·04 per cent., which indicates the presence of comparatively large reserves of potash in these soils. No relation was found to exist between the total potash, and the quantities soluble in hot concentrated hydrochloric acid.(3) The average value of the HCl-soluble potash was 0·50 per cent, and in the profile samples there was generally an increase in solubility with increase in depth of soil.

Description: This series of investigations embraces studies of the more important factors, external and internal, which govern yield in field crops of cereals. It has so far dealt with the causes and influence on yield of fluctuations in density of plant population and also with certain inter-field differences of environment. Throughout, an analytical method has been employed, in which periodic observations have been made upon small samples distributed over a representative acre in a field crop. The best size of sample has proved to be a one-foot length of row, i.e. row of plants as seeded by the drill. The basis of this method—a “census” of an acre of corn—has been described and critically examined in an earlier paper (Engledow(1)). Analyses of certain external factors affecting yield have been recorded by Engledow(2) and by Doughty and Engledow(3).

Description: Milk which has been heated to temperatures varying from 105–209° F. for half an hour differs from raw milk in its reaction to rennet in all cases.There is no change in the diffusibility of the nitrogenous substances in milk after heating to temperatures varying from 105–209° F. for half an hour.Heating to 175° F. and above for half an hour appears to reduce the diffusibility of the phosphorus content of milk.Heating to 125° F. and above for half an hour causes marked diminution in the diffusibility of the calcium content of milk.

Description: During the carrying out of the series of researches which led to the formulation of the well-known expression for calculating the starch equivalent of a feeding stuff, Kellner(1) was led to investigate the value of crude fibre in the fattening ration of oxen. For this purpose he used material which had resulted from the boiling of rye straw with an alkaline solution under pressure, the object of this treatment being to free the cellulose of the straw from incrusting substances. This fibre-rich preparation was added to a basal ration which was slightly in excess of maintenance requirements. The result produced by the addition to the basal ration of the digestible matter derived from the fibre of the treated straw was found by Kellner to be equal to that produced by the addition of an equal weight of pure starch. The conclusion was therefore warranted that the digestion products of cellulose in the ruminant organism are equal, for purposes of fat formation in the body, to those derived from the digestion of starch. This finding is given practical expression in Kellner1s formula for calculating the starch value of a feeding stuff, an equal value being attached to digestible fibre and digestible carbohydrate.It is clear that any theory which is put forward to explain the breakdown of cellulose in the ruminant tract must be compatible with the experimentally demonstrated fact that the products of such digestion of a given weight of digestible fibre are equal in nutritive value to the products derived from the digestion of the same weight of starch.

Description: The principal factors influencing the yield and quality of milk are (1) stage of the lactation period, (2) breed of the cow, (3) interval between milkings, (4) age of the cow, (5) individuality of the cow, (6) efficiency of the milker, (7) temperature and weather conditions, (8) health of the cow, (9) feeding.

Description: 1. Under the extremely humid conditions obtaining in N. Wales, with soils showing a high degree of base-unsaturation, phosphoric acid applied to permanent grassland as basic slag is fugitive in its effect.2. From profile analyses it is shown that after six to ten years added phosphoric acid is removed from the surface layers, which revert to their original phosphorus status.3. It is suggested that the phosphorus of soils may be differentiated into that of the naturally occurring stable phosphates and the phosphorus of added dressings which is, under N. Welsh conditions, unstable and removable by percolating waters.

Description: A lighting (paraffin) oil bought casually, such as is often used in paraffin emulsions for spraying, has been subjected to fractional distillation, and shown to be unsuitable as a spraying oil.Approximate solubilities at room temperature of various “oils” in solvents such as soap solutions with and without the addition of phenols, hydrogenated phenols and pyridine, have been determined. Spray fluids containing paraffin oil, benzene, and aniline in solution are economically possible, but coal tar fractions such as anthracene and creosote oils, will, owing to lack of solubility, have to be applied to plants as emulsions. Cresylic acid is the best aid to solution of paraffin oil, but is probably more injurious to foliage than the dearer, hydrogenated phenol, hexalin.Experiments have been made on the influence of temperature when using soap (sodium oleate) and gelatine as emulsifiers; rise in temperature is found to facilitate the formation of emulsions in soap solutions, but to have a much more complex effect when gelatine is the emulsifier. A possible explanation of these facts is given.

Description: An attempt has been made to ascertain the best interval between calvings, so that the cow's average weekly yield over a long period may be at a maximum. It was only possible to consider the case of the “average cow,” but it is claimed that the general principle has been established, that cows should calve at intervals of not less than a year, and not more than thirteen months; this optimum will probably be subject to a slight variation in particular cases. This is approximately the state of affairs in practice—though Norfolk farmers appear to err on the side of serving too early in the lactation, rather than too late.

Description: The object of this series of investigations is to secure detailed information concerning the composition, digestibility and nutritive value of pasture grass in its different stages of growth. The results which were obtained in these respects by cutting the herbage of the experimental pasture plot at weekly and at fortnightly intervals have been described in previous communications. During the season of the present experiment, the trials have been carried a stage further by the adoption of a system of cutting at 3-weekly intervals. The main findings of the 1928 investigation are recorded below:(1) Chemical composition of 3-weekly pasture cuts: The adoption of a more lenient system of cutting at 3-weekly intervals led to a slight lowering of the percentage of crude protein in the grass and a slight raising of the percentages of crude fibre and N-free extractives. On the other hand, no corresponding effect was noted in respect of the ether extract, SiO2-free ash, lime and phosphate, the percentages of these constituents being very similar in the weekly and 3-weekly pasture samples obtained in 1928. The falling off of the percentage of crude protein in the 1928 3-weekly-mown herbage, as compared with the weekly and fortnightly-mown herbage of 1925 and 1927 respectively, was not wholly the consequence of the more lenient system of cutting, but was also due in part to the protein-depressing influence of the droughty periods which were experienced in the 1928 season.

Description: 1. There exist in Trinidad large areas of deteriorated soils which have been under cultivation with a single short-term crop for generations. It has previously been established that these soils differ but little from those which still retain their fertility in their content of organic matter. By comparison with the latter, however, they are markedly acidic and so deficient in exchangeable calcium that a material improvement in their lime status appears to be a necessary preliminary to their amelioration. An examination has therefore been made of the means by which this may most successfully be accomplished.2. Determinations of the contents of exchangeable calcium and the pH values of a series of liming experimental plots indicate that:(a) Contrary to experience in England, finely ground limestone has proved a more efficient soil ameliorant than slaked lime.(b) Single relatively large applications of lime fertilisers have given more immediate beneficial results than small annual dressings.(c) The effect of liming appears to have been almost entirely restricted to the depth to which the soil is worked. This is doubtless due to the impermeability and lack of aeration which characterises heavy deteriorated soils.3. A significant increase in crop yield was obtained only on those plots which were later shown to have been rendered neutral in reaction by liming, and on which the degree of saturation of the top 6 in. of soil has been raised to 80 per cent. This value is comparable with that of the fertile soils of Trinidad.4. The experience of liming methods gained in Trinidad may be applicable to other areas of alluvial soils under cultivation in the tropics.

Description: 1. Material is presented which shows month by month the lactation yields of cows in respect of milk and fat. Morning and evening yields are treated separately and differences in relative proportions found.2. Smaller proportions of milk and of fat at the morning milkings are yielded in early lactation by all cows, but this point is most pronounced in heifers and also in heavy yielding cows with relatively small udders. It is suggested that with such animals reabsorption of milk occurs during a long night interval.3. Seasonal variations in yield of milk and fat are shown. It is found that the morning milking does not respond as much as the evening milking to the stimulus to secretion which functions during May and June.4. The quality of milk at different seasons of the year is discussed.

Description: 1. A method for the rapid determination of lime requirements in laboratories equipped with the quinhydrone electrode is described. (10 gm. of soil are mixed in a small wide-mouthed bottle with 40 c.c. of neutral 0·2 M CaCl2 solution. The mixture is then titrated with 0·03 N lime-water in successive portions of 5 c.c, with three minutes' shaking between each addition. The pH value of the mixture is determined after each addition, and the titration continued until the reaction has passed pH 7·0. The results are plotted, and the exact volume of limewater needed to give a final reaction of pH 7·0 is estimated from the graph.)2. The method is compared with the Hutchinson-MacLennan method for a series of soils of different textures and different initial exchange reactions. It appears to yield more reliable results; it is less tedious; it is very rapid, and results obtained thereby can readily be reproduced.

Description: (1) It is proposed to estimate the amount of organic carbon in soils by determining the amount of sulphur dioxide produced in the ordinary Kjeldahl digestion. The gaseous products of reaction are passed through standard iodine solution, and the excess iodine titrated with standard sodium thiosulphate. Details of the method are given.(2) The results obtained with a number of soils of differing character and origin are compared with the figures obtained for organic carbon by dry combustion. The sulphur dioxide method gives results which average 89.6 ±1.03 per cent, of the combustion figures. It is proposed therefore that the percentage of organic carbon found by this method should be corrected by the factor 100/89.6 = 1.116.(3) The percentage recovery of carbon indicated by the proposed method is rather higher for pure substances but still falls short of 100 per cent.(4) The proposed method is applicable to carbonate soils without the necessity for any correction for inorganic carbon.(5) It is likely that soils containing inorganic reducing substances such, as sulphides will give high results by the proposed method.(6) Absorbing the sulphur dioxide in 25 per cent, sodium bichromate, it is possible to determine the carbon dioxide by passing the gases through standard baryta in a Reiset tower. The organic carbon thus indicated agrees with that by the sulphur dioxide method.(7) From data with certain peats, it appears that the factor 1.724 for converting organic carbon to organic matter is too low.

Description: Inconsistency in the returns of sugar percentages from the factories has often perplexed growers and has at times given rise to some mistrust of the analytical procedure. Consignments of beet lifted on the same day and from the same field have been credited by the factory with widely different sugar contents. This has occurred within the writer's experience, even though the precaution was taken of loading the cart loads of beet into two trucks alternately, thereby eliminating any possibility of one truck being filled with beet from a better part of the field than the other.

Description: 1. Both Pseudoperonospora Humuli and Phytophihora infestans are extremely susceptible in the zoospore stage to the action of weak solutions of soap or saponin. The zoospores are caused to disintegrate suddenly, apparently by changes in surface tension, within 60 seconds, in solutions containing over 0·1 per cent, soft soap. Those of P. Humuli are more vulnerable than those of P. infestans.2. The fungicidal action of soap and saponin mixed with certain adherent substances was tested on hop plants.3. The power of adhesion and the fungicidal efficiency of the mixtures were tested by allowing single drops to dry on the surface of watch glasses and by then adding drops of water containing zoospores.4. Other substances, e.g. aluminium-lime mixture, glycerine, iodine, bromine, were also found to kill zoospores rapidly.

Description: Organic materials with a C: N ratio ranging from about 85: 1 to about 10: 1 were submitted to nitrification tests in an acid and in an alkaline soil during a period of 6 months. In the acid soil only pea pod meal, with a C: N ratio of 13·3: 1 showed an increase in inorganic N over control; in the alkaline soil the limit above which no nitrification will occur within a period of 6 months was at C: N = 26: 1; below this limit the rate of nitrification increased rapidly with decreasing C: N ratio. Unnitrified N was left behind in a quantity corresponding to 1·5–2·2 per cent, of the original material, the percentage being higher in the case of materials rich in N.All the materials tended to increase the content of “a-humus” in the soil, though not to the same extent or in the same manner. More “a-humus” was produced in the alkaline than in the acid soil, except in the case of farmyard manure. Straw, sweet clover, lupin and farmyard manure apparently acted both through their lignin content and through the synthesising action of microorganisms, since they increased the amounts of both N and methoxyl in humus. Mycelium of Polyporus contains a fraction possessing the properties of “humic acid,” rich in N, but devoid of methoxyl, which persists in the soil.

Description: The metabolism of a Berkshire and a Middle White pig has been investigated by means of the calorimeters at the School of Agriculture, Cambridge. The general routine and technique of the observations have been as heretofore.Measurements of the fasting katabolism of each of the two pigs have been obtained in a series extending from an early age to maturity, and the phenomena in general follow the lines of those originally discovered in the Large White; but the fasting katabolism of the Middle White was below that of the Large White earlier studied.The fall in body temperature and in metabolism during the fasts were found to be correlated, and the possible effect of skin colour in this matter is noted.The effect of environmental temperature is investigated and reasons are given for supposing that the critical temperature of the Middle White pig is very low.It is concluded that the existence of a maximum somewhere in the curve showing fasting katabolism per unit area at different ages is necessitated by the two physiological facts (a) that warm blooded animals have to be maintained at a temperature which varies only within very narrow limits, and (b) that the processes of growth are accompanied by waste of energy as heat.

Description: 1. The sugar-cane in Trinidad is subject to blight, caused primarily by the sucking action on its leaves of a Cercopid, Monecphora (Tomaspis) saccharina Dist., commonly known as the “froghopper.” The intensity of the injury sustained by the cane appears to depend largely on the condition of the soil in which it is grown. An investigation has, therefore, been made of the extent to which certain soil factors are associated with the reaction of the cane to froghopper attack.2. The data obtained show that the mechanical composition of the soil and its content of organic matter bear little relationship to the damage caused. The blighted soils differ from those blight-free, however, in that, whereas the former are devoid of calcium carbonate and, as a rule, markedly acid, the latter almost mvariably contain at least traces of this substance, and in general are alkaline or slightly acid only. These differences suggest that the lime status of the soil is a factor of primary importance.

Description: 1. The paper discusses experiments laid down at 39 centres in Great Britain to test the value of seed inoculation for lucerne.2. The seed was inoculated by treating it with a suspension of the nodule bacteria in skim milk containing 0·1 per cent, calcium di-acid phosphate, the method developed by Thornton and Gangulee.3. In the west and north of England the treatment greatly benefited the lucerne and often enabled a crop to be obtained where the untreated lucerne failed. At 12 centres in this area at which the crop was weighed, inoculation increased the yield by over 20 per cent, in all cases save one, where spread of the bacteria vitiated the result.4. The improvement sometimes showed itself as an increased yield and sometimes as an increase in the nitrogen content of the hay. In most cases both these effects were produced.5. In the midland and south central counties inoculation usually produced a temporary improvement, the untreated plant eventually catching up with the inoculated. The effect of inoculation is very much greater where the young lucerne has to compete with a cover crop. Weight results from 8 centres in this area showed increases from inoculation of over 20 per cent, in 4 cases, smaller but significant improve-ment in yield or nitrogen contentin 3 cases, and no significant effect in one case.6. In East Anglia and Kent untreated lucerne usually develops plenty of nodules. An exceptional condition occurred in a trial at Tunstall Heath, Suffolk, on sour light land, where liming and inoculation produced a fair plant although the uninoculated lucerne developed no nodules and failed.7. There is evidence that, when the seed is inoculated, the chances of success with lucerne are on the whole as good in the west and north of England as they are in the south-east.8. In a number of trials sown in 1926 better results were obtained by sowing the seed in a light cover crop in spring than by sowing in June or July.

Description: 1. An account is given of the geology and mineralogy of the soils of a small area characterised by diverse rock groups, which are mainly covered by glacial drift. The topography is also varied. The soils are mainly derived from boulder clay, glacial sands and gravels, and alluvium, the remaining soils being formed on screes and hill-wash. The underlying rocks are lavas of Old Red Sandstone age and sandstones and shales of Carboniferous age.2. A similarity in mineral content of the soils on glacial material and alluvium is shown. All these soils have a high content of fresh ferro-silicates. The soils on the screes and hill-wash are characterised by their content of rock fragments and iron oxides, but minerals from glacial material are also present, though to a minor extent.3. The soils on the drift material contain potash, phosphate and lime-bearing minerals.4. The varied nature of the parent materials has given rise to varied textures in the soils. The soils on the boulder clay are the heaviest, while, the soils on the fluvio-glacial material are very variable.5. The mineral content of the matrix of the boulder clay is similar to that of the local rocks, only the rarer minerals being derived from external sources.

Description: The problem of the use of water by cultivated plants during the period of their growth is of great scientific interest. It is certainly of prime interest for the farmers of a dry region where to secure a yield everything depends in most cases upon the problem of moisture.When studying the problem of the use of water by cultivated plants under field conditions the importance of extremely unstable and widely varying meteorological factors is evident. The fluctuations are especially large and irregular with respect to moisture.

Description: 1. The Valmari-Devarda method of estimating nitrates (i.e. distillation with magnesium oxide and Devarda's alloy) is unsatisfactory in presence of organic matter. Attempts to make it quantitative under these conditions by modifications of alkali and temperature proved unsuccessful.2. Two new methods for the estimation of nitrate in plant juices are described. The first depends on the use of Devarda's alloy in cold weakly alkaline solutions, the second on the reducing power of titanous hydroxide, under conditions suitable for use with plant products.

Description: 1. 670 samples of the mixed milk from 15 herds were analysed, and the average percentages of total ash, soluble ash, insoluble ash, lime and phosphoric acid are given.2. Tables showing frequency distributions are also given, with the standard deviation, mean and probable error of mean for each constituent determined.3. Various correlations of these constituents with solids not fat and protein have been prepared, and these correlations are illustrated by graphs.It is observed that the total ash falls with the solids not fat until low values of solids not fat are reached, when the ash content appears to rise. This variation is confirmed by a curve illustrating the variation in ash content of samples of individual cow’s milk. Soluble ash rises as the solids not fat falls, but the insoluble ash shows a reverse variation. Lime and phosphoric acid both fall with the solids not fat.

Description: 1. Sudan soils are very low in organic matter, the total organic carbon being usually less than 1 per cent. In the Gezira, the humus carbon is about 40 per cent, of that of the total.2. Humus preparations purified as far as possible could not be obtained ash-free. Specimens of humus from widely different sources contain nearly the same proportion of carbon.3. Humus solutions (in very dilute alkali) keep fairly well in the dark. They also keep in bright sunlight if air is excluded. The use of standard solutions for colorimetric purposes is justified if not kept too long.4. Field studies show that the humus content of good soil is greater than that of poor, and that there is a marked inverse connection between salt and humus content.5. The above conclusion does not apply to the depth distribution of these constituents. In the Gezira, the maximum humus content is found at the fourth foot and the maximum salt content is found at about the same depth.6. The total nitrogen content of the soils studied is low, usually about 0·03 per cent. About one-fifth of this is humus nitrogen, and the carbon-nitrogen ratio is about twelve to one.

Description: During recent years a growing interest has been manifested by feeders of stock in the form of cooked maize known as flaked maize, which is produced on the industrial scale by the steaming and rolling of maize grain. Following the publication of the results of an investigation into the comparative values of dry, soaked, cooked and flaked maize for pig-feeding, in which investigation the high digestibility and feeding, value of flaked maize were amply demonstrated, frequent enquiries have been received as to whether it is justifiable to assume an equal feeding value for the several brands of flaked maize which are put on the market at the present time.

Description: In a previous paper (Davies, 1926) the author studied the differences in the compositions of protoplasmic proteins of plants within a Natural Order (Leguminosae). The Natural Order Cruciferae afforded a means of developing the study in the direction not only of ascertaining differences, if any, of protoplasmic protein of plants within a genus, but also of differences possible within a species. Thus proteins were studied from the following varieties of the cabbage species (Brassica oleracea L.): Cabbage (B. oleracea var. capitata), Marrow stem kale (B. oleracea var.) from the stems and leaves separately, Kohl rabi (B. oleracea var. caulorapa). Also, the proteins from the leaves and roots respectively of white turnips (B. napo-brassica) were isolated and studied. In order to compare the protoplasmic proteins with those of seed of a plant of the same species, a globulin from rapeseed (seed of Brassica Napus L.) was prepared and analysed.

Description: 1. The moisture equivalent of pure clay preparations varies with (a) the chemical composition, (b) the method of separation if centrifuged, (c) the replaceable bases.2. The imbibitional water content also shows a close connection with the above variables.3. Good additive relationships can only be obtained from series of soils of the same nature and in some cases, if taken at the same depth. This is, at any rate in part, due to differences existing in composition and properties between clay separated from soils and subsoils.4. Pure silt fractions from different soils showed marked differences in their chemical composition and moisture equivalent.

Description: G. W. Robinson and J. O. Jones (1) have shown that humified can be distinguished from non-humified organic matter by the use of 6 per cent, hydrogen peroxide. Humified organic matter is apparently oxidizedor rendered soluble by this reagent, whilst structural organic matter is unattacked. It seems reasonable to suppose that a similar distinction might be made in the case of farmyard manure between the amorphous decomposed material and the unaltered fibre of the faeces and litter. In other words, the degree of decomposition of farmyard manure might be determined by a method similar to that suggested for the degree of humification of soil organic matter. It is recognised that farmyard manure differs somewhat from soil organic matter in that the former includes the naturally soluble constituents of the litter, faeces and urine, which are either oxidized completely or rendered soluble in the peroxide treatment. However, they may be regarded as analogous in that both have undergone putrefactive decomposition. In the present paper, humification is used as a convenient term for the processes whereby organic matter is changed to structureless colloidal material and not as implying their exact correspondence with humification in the soil.

Description: The plants worked on in this Natural Order were the Carrot (Daucus carota L.) and the Parsnip (Peucedanum sativum Benth.). Both these plants store up reserve food in their thickened root and hypoeotyl, the disposition of the tissues being similar in both “roots.” For the extractions of their proteins, members of “races ” of these plants containing the minimum amount of core and fleshiest annuli of bast were taken, healthy, uniformly well-grown specimens being selected.

Description: (1) The formation of laterite and lateritic soils in Sierra Leone has been studied and the mode of formation and the composition of these soils is described.(2) It is suggested that since the clay fraction is regarded as the most important fraction in determining the reactions of a soil the classification of laterite and lateritic soils should be based on an examination of the clay fraction. It is further suggested that where the silica/alumina ratio in the clay fraction falls below 2·0 the soil should be described as “lateritic,” and where this ratio falls below 1·33 the soil should be described as laterite.

Description: The addition of sodium silicate has been found to increase the yield of barley to a considerable extent, this effect being most marked when no superphosphate is added.The phosphatic content of the ash is not greatly increased in the grain, and is diminished in one case in the straw; the conclusion from this observation that the silicate does not act by releasing soil phosphates, but as a plant stimulus, overlooks the fact that the addition of silica to the ash naturally reduces the percentage of other constituents, and should be discounted.The phosphate removed annually in the crop is greatly increased on the plots receiving silicate, even when this removal has continued for many years without replacement.That additional phosphate is actually made available to the crop on the plots receiving silicate is shown by the increase in the proportion of phosphate in the dry weight of the crop, which appears on all the plots, and at all periods.This increase is quantitatively sufficient to account for the increased yield in grain and straw, without postulating the aid of any stimulus to plant growth.

Description: 1. The form of the dispersion curve obtained by single dispersion treatment below μ/x varies greatly with different soils and with the same soil saturated with different bases. There is no connection between the proportion of very fine material (e.g. below 0·5μ) and other important soil properties. The proportion of the very fine material determined in this way would not, therefore, afford any indication of the “colloid” properties of the soil. If the proportion of fine material were estimated by a decantation method the results might be substantially modified.2. Under the same conditions of dispersion sodium soil is better dispersed than ammonium. Sodium carbonate should therefore be the best medium for mechanical analysis.3. No case has been met with where the proportion of clay found is affected to an important degree by the use of hydrogen peroxide.4. With no soil tried was the number of decantations reduced by the use of acid pre-treatment; those examined gave the same clay content i f sufficient puddlings with sodium carbonate were used with or without acid.5. No method has been found whereby certain soils can be dispersed i n a single operation as is required in the pipette method. In some cases this is due to gypsum, but there are others in which the cause of the difficulty of dispersion is not yet known.6. In the cases examined sodium carbonate gives a higher result than ammonia when using the International pipette method.7. For Sudan soils decantation methods appear essential, hydrogen peroxide unnecessary, acid pre-treatment not essential, and sodium carbonate better than ammonia. We are of opinion that the same holds good for many other soils.

Description: The results of the investigation may be summarised as follows:(1) In Egypt, during the periods of germination and increase in height of the cotton plant, the soil temperatures are rising and the amplitude of the temperature wave is at its maximum.(2) In Egypt, the maximum soil temperatures decline while the minimum soil temperatures remain constant, thus resulting in a gradual decrease in the amplitude of the daily temperature wave during the branching and flowering periods.(3) In Egypt, throughout the soil zone occupied by the roots of the plant, the temperature is the same, the amplitude of the daily temperature wave small, and the temperature is constant during the boll development and maturation periods.(4) The main effect of irrigation on soil temperatures is to reduce the amplitude of the daily temperature wave, no sudden change of temperature in the root zone taking place.(5) From a consideration of the range of air temperature in other cotton producing countries, it seems probable that the characteristics of the soil temperatures during the boll development and maturation periods are the same for all countries.

Description: Rothamsted and Indian soils were water-logged in the absence of freshly decomposing organic matter.Nitrogen changes: Water-logging resulted in:(1) A distinct increase in the free and saline ammonia content.(2) A significant though only slight diminution in the nitric nitrogen.(3) No marked loss of ammonia by volatilisation or otherwise in the gaseous form: nor considerable variation in the nitrites: nor any observable diminution in the total nitrogen.Reaction: Water-logging resulted in an increase in alkalinity; the increase in pH value was closely correlated with the corresponding increase in ammonia.Gaseous relations: Water-logging resulted in:(1) No release of any soluble reducing matter capable of absorbing dissolved oxygen.(2) No appreciable carbon dioxide production.(3) An absorption of dissolved oxygen from the surface water. An equation has been worked out expressing the concentration gradient of dissolved oxygen with depth.Bacterial numbers:From bacterial counts on water-logged soils it was found that:(1) There was significant though slight decrease in bacterial numbers on Thornton's Agar.(2) Very few colonies were obtained by plating aerobically (and fewer still anaerobically) on Giltay's Agar. None of the organisms appearing on the plates brought about any nitrate reduction in soils.(3) The total counts on gelatine plates also showed some decrease. The numbers of gelatine-liquefiers on the other hand did not vary. There was no evidence to suggest that the increased production of ammonia was due to the activity of the gelatine-liquefiers.Agency responsible for ammonia formation:The results indicate that the formation of ammonia in water-logged soils is not due to biological action. It is suggested that the action is due to an enzyme.

Description: During recent years a large number of samples of milk having a peculiar flavour have been sent to this Institute by farmers, retailers, and wholesalers of milk.The flavour is marked and has almost invariably been described as “oily.” In many instances it has been referred to as the “castor oil flavour.”Although, as would be expected, the opinions of individuals on the flavour of such samples were not unanimous the majority agreed that “oily” was an appropriate name and since this is the name by which this taint is known to the trade it is proposed to retain it.

Description: In a former communication (1) a study has been made of the influence of the stage of lactation on the yield and quality of the milk, and in the following paper a similar investigation has been made of the influence of the age of the cow on the same factors.Mackintosh (2) finds a gradual increase in yield up to the 4th or 5th lactation period, and a decrease after the 7th or 8th; thus a heifer calving at 2¾ to 3 years gives 60–70 per cent. of the amount it will produce as a mature cow; after the second calf it gives 80 per cent. and after the third 90 per cent. Tocher's results (3) show an increase from 85 per cent, of the maximum yield at 3 years to a maximum at 7½ years, and a subsequent fall to 90 per cent. at 12 years of age.

Description: (1) Exchangeable magnesium and potassium can be determined in carbonate-free soils by the use of 0.5 N acetic acid as a leaching agent.(2) A method is described for the determination of the total exchangeable bases present as acetates in the leachings.(3) The results obtained by this method differ from those obtained by summation of separate determinations by an amount equivalent to the sulphates and chlorides present.(4) It is suggested that the total exchangeable bases by the proposed method gives a truer measure of the exchangeable bases than methods in which bases present as sulphates and chlorides are also reckoned in.

Description: 1. The day to day variability in the yield of milk and fat of cows is affected by many factors, two of which are stage of lactation and season of the year. Variability is high during the first month of lactation (particularly during the first few days after the calf is weaned), but after this a fairly constant variability may be expected. Under the conditions of management in the herd under discussion and probably in most herds in Southern England variability is highest during the month of May and also tends to be higher during the summer than the winter months.2. A method is presented of calculating the variability in the yield of mixed milk from a herd of cows and the error to be expected when milk records and fat percentages of individual cows are calculated from a few samples.3. When cows are milked twice daily at unequal intervals the yield of milk obtained in 24 hours is slightly less variable if a morning milk yield is added to the subsequent evening yield, than if an evening yield is added to the subsequent morning yield.

Description: 1. The acid method previously described has been used to evaluate samples of pyrethrum derived from both Swiss and Japanese seed, with equally successful results.2. A rapid method for the evaluation of pyrethrum by a determination of pyrethrin I is described.

Description: (1) Animals on a calcium-deficient diet suffer periodically from loss of appetite though the ration is in every other respect satisfactory.(2) The results of twenty-two digestion trials show no enhanced effect on the digestibility of the organic constituents of the food on adding calcium carbonate to a lime-deficient ration.In conclusion, I wish to express my thanks to Prof. T. B. Wood, F.R.S., for giving me the necessary facilities to carry out the work; to Mr H. R. Davidson, M.A., for placing the experimental animals at my disposal and also to Dr H. E. Woodman for his active interest and supervision at all stages of the work.

Description: The scheme of soil classification which finds most favour among scientists to-day has come from Russia and is the work of a band of brilliant and enthusiastic investigators whose labours have brought some order to what was otherwise chaos. The object of this communication is to endeavour to show how it is possible to modify the views of this school so as to make them apply to British conditions, and how the majority of British soils may be brought within the envisaged scheme.

Description: (1) The physiological effects of calcium-deficiency on pregnant sows are briefly discussed. Results are given which demonstrate that a deficiency of lime in the food has no detrimental effect on the live weight of the young piglings at birth thus showing that up to parturition it is the mother organism that suffers and not the offspring.(2) Storage of nitrogen takes place throughout pregnancy but the results indicate a considerably enhanced conservation within three weeks of parturition. The average daily retention of nitrogen by the high-calcium group of sows was 12·51 gm. and by the calcium-deficient group 9·78 gm. The normal sows therefore stored 1439 gm. N and the calcium-deficient 1125 gm. N during the gestation period. It is shown that storage of protein during pregnancy is greatly in excess of the foetal requirement, so that the mother organism, during gestation, adds on a reserve supply of protein in preparation for parturition and lactation.(3) Ash ingredients were retained at all stages of gestation by both groups of sows. The addition of calcium carbonate to the food, however, resulted in an increased retention of ash. The percentage of the ash intake in the faeces was very similar in both groups, but the percentage of the intake in the urine was distinctly higher in the calcium-deficient sows indicating a more economical utilisation of ash by this group.

Description: (1) A solution of dicalcium hydrogen arsenate at a strength of 0·0125 per cent. As2O5 was fungicidal to the conidial stage of Sphaerotheca Humuli, while at 0·006 per cent. As2O5 it was not quite fungicidal.(2) Lime casein containing calcium hydroxide when added as a spreader to calcium arsenate was shown to reduce the fungicidal properties of the calcium arsenate spray.(3) A solution of calcium thioarsenate at a strength equivalent to 0·006 per cent. As2O5 was fungicidal to the above fungus, while at 0·003 per cent. As2O5 it was below fungicidal strength.(4) It is suggested that the increased fungicidal properties of the mixed lime sulphur-lead arsenate spray are due to the presence of calcium thioarsenates.

Description: The development is recorded of the series of experiments with potatoes at Rothamsted during 1925–27, designed to examine the quantitative response of yield to varying quantities of nitrogenous and potassic manures, and to test the relative value with this crop of different sources of potash.While rather precise comparisons were obtained on the qualitative question by means of Latin squares in 1925–26, the reality of the depression ascribable to chloride could not be demonstrated in these years, but became clearly apparent when in the following year, the qualitative experiment was merged with the quantitative one.In the earlier quantitative experiments, although satisfactory responses were obtained, the precision of the results left much to be desired, since only four replicates could be used. When by merging the experiments this was increased to nine replicates, much smaller responses were clearly measurable.The large and complex type of experiment finally adopted thus supplied more precise information on both heads than could previously be obtained, and in addition to a more thorough exploration of the different combinations possible.

Description: (1) A gasometric method for the determination of organic carbon in soils by the use of sulphuric-chromic acid mixtures at 100° C., as suggested by Watts in 1902, is described, and recommended for use in routine soil analysis.(2) The method is compared with the Kjeldahl procedure recently introduced by Robinson, McLean and Williams, and is found to give results which are generally similar, though numerically slightly lower.(3) The wet combustion method is somewhat simpler than the Kjeldahl method, but it has the disadvantage that nitrogen determinations cannot be made simultaneously, so that its usefulness in studies on soil organic matter is decidedly less.

Description: Experiments were carried out at two centres in Leicestershire during the spring of 1928, with the object of comparing the values of mangels and dried sugar beet pulp in the winter ration of dairy cows.Two groups of cows were selected at each centre, and the usual method of feeding for a period on one ration and then reversing, was adopted. Composite samples of the milk from each group of cows were taken at six consecutive milkings per week, during the period of the experiment. Determinations of fat and solids not fat were made, and the yield of milk at each milking recorded.Although there are indications that the change of ration caused a slight temporary variation in the quality of the milk, the secretion of milk solids followed, in a general way, the variation in yield: This is confirmed by the average composition figures representing the whole of the milk from each particular ration.Thanks are due to Mr Thos. Hacking for placing every facility for obtaining these data at the disposal of the author.

Description: The investigation bears out the conclusion of the Rothamsted experiments that leaching out may occur any time throughout the winter up to March, or rarely April.The loss of nitrates is directly limited by the amount of drainage and so is indirectly determined by the rainfall, and by temperature—as it affects the rate of evaporation.All three nitrogenous fertilisers are shown to lose well over 50 per cent, of a normal dressing by leaching out during the winter, but the loss is greatest in the case of sulphate of ammonia, least in the case of rape dust, calcium cyanamide being intermediate.The writers wish to express their indebtedness to Miss N. Sugg who carried out the experimental work in the first winter.

Description: In the past the standard method for determining the chloride content of soils has been to titrate with silver nitrate using potassium chromate as indicator. In most cases, the soil must be filtered through a filter candle and where in favourable cases filtration can be dispensed with, it is necessary to wait until the soil has settled before aliquot portions can be pipetted off and titrated.

Description: In a field trial with lucerne grown from seed treated with varying doses of culture it was found that the numbers of nodules were increased as the dose was raised from 2,500 to 20,000 organisms per seed (56 to 7 Ib. of seed per culture). Storing the seed for periods up to 28 days between inoculation and sowing, caused some loss in the nodule numbers. This loss was greatest between 1 and 7 days' storage.The difference in dose of culture and in period of storage did not significantly affect the crop subsequently obtained from the inoculated plots, whose yield was, however, much above the uninoculated.In a pot experiment made with runner beans, it was found that increase in the dose of culture above 1,280,000,000 organisms per pot containing six seeds was still capable of increasing nodule numbers but not to an extent proportional to the increase in dose.The experiment does not exclude the possibility that the restriction in effect of very heavy doses may be due to the soil population becoming saturated with the bacteria. On the other hand, observations on lucerne plants grown aseptically on agar and inoculated with a pure culture, showed that even when excessive numbers of the bacteria immediately surrounded the root hairs, only 4 per cent, of these were infected.

Description: 1. (a) Pyrethrin I and II have been isolated by the method of Staudinger and Ruzicka from the insecticidal plant Pyrethrum (Chrysanthemum cinerariaefolium). Both are shown to be highly toxic to the insect Aphis rumicis.(b) Pyrethrin I was found to be the most toxic substance so far tested by us and, as it was about ten times as toxic to these insects as pyrethrin II, it is concluded that it is mainly responsible for the contact insecticidal value of pyrethrum.2. Two micro-analytical methods of determining the pyrethrin content are described, (a) By means of the acids after hydrolysis, (b) By means of the semicarbazone. They are given on pp. 278, 282.3. The analytical results obtained for a series of pyrethrum samples agreed with their observed insecticidal properties to Aphis rumicis.4. Comparisons of the pyrethrin contents, as estimated, with the results of direct toxicity experiments both on the pyrethrum samples and the pure pyrethrins, confirm the validity of the analytical methods.5. There was a significant and positive correlation, in the samples tested, between the amounts of pyrethrin I and II.6. Insufficient data are available to show a significant correlation between the size of flower-heads and the content of poison, or to draw conclusions as to the effect of external conditions such as soil, weather or age of bed.

Description: The occurrence of xanthin calculi in the kidneys of sheep on certain poor pastures on the Moutere Hills in the Nelson district is reported and described. The incidence of xanthin calculi is associated with poor stock results over large areas. Poor lambing returns, high mortality of stock in certain seasons, low milk yields and inability to fatten stock are common features of many farms on the Moutere Hills soil. On one small farm, grazing 120 sheep, no less than 12 sheep which have died or have been killed during the last six months have had calculi in the kidneys.The Moutere Hills soil type is shown to be highly deficient in both lime and phosphate. Great increase in crop production invariably accompanies the application of lime and phosphate to the land.

Description: In an attempt to determine the rôle of phosphates in tomato culture tomato plants have been analysed for potash, phosphoric acid and nitrogen.In unmanured plants the fruit is of inferior quality but the weight as picked is 2·6 times that of the foliage and stems of the same plants. In manured plants this ratio is 1·6. The relative efficiency of the plants under the two sets of conditions is discussed.Manured plants have a higher ash content than unmanured plants.

Description: 1. The variations in production due to age have been investigated with the records of 738 Ayrshire cows for 4380 lactations.2. Milk and butterfat production increase up to about 7 years of age and then show a decrease.3. The fat percentage for 3-year-olds is higher than that for older cows.4. After 3 years of age there is little change in the fat percentage with age that is of any practical significance until advanced ages are reached, when there may be a fall of importance.5. The increase in production associated with age is probably attributable, in part, to the growth of the secretory tissue of the udder and to body growth in general.6. Part of the increase may also be due to an improvement in functional activity through use.7. The tendency for milk to show a slightly lower fat percentage as the cow advances in age is probably due to the fact that as the milk yield changes the fat yield changes in the same direction but at a slower rate.8. There is little known regarding the influence of very advanced age on production, but it is probable that many cows maintain for a long time the production associated with maturity, and then decline slowly.9. Heifers with a low fat percentage need not as a rule be expected to test higher on reaching maturity.10. It is probable that the increase in production with maturity is associated more closely with high initial production than with persistency of production.11. Correction factors for age are presented.

Description: 1. Records are offered of year old cattle reared to adult weight on rations of varying content in respect to calcium, phosphorus, sodium, potassium and chlorine. Minimal requirements for growth are higher in the case of phosphorus than in the case of calcium, and a ratio of P2O5 to CaO so high as three to one is not necessarily disadvantageous. Sodium requirements for growth are very low, 2 gm. Na2O being more than sufficient. Chlorine requirements are below 5 gm. per day. A relatively high ratio of potassium to sodium is not productive of specific disease. There is no good reason to suppose that excess of basic over acidic constituents is necessary in a dietary, and cattle can grow normally to full adult weight when the usual alkaline reaction of the urine is shifted to the acid side.2. Explanation of certain observed abnormalities in calving is left open, except in the case of phosphorus deficiency, in which definitely abnormal calves may be born.3. “Aphosphorosis,” or clinically recognisable phosphorus deficiency disease, is experimentally produced, and shown to be identical with the naturally occurring South African disease Styfsiekte.4. The chemical composition of the milk of animals suffering from aphosphorosis meed not mecessarily be abnormal, but the “inorganic” fraction of the blood may drop to a quarter of the normal value even before the disease can be diagnosed clinically. Other phosphorus compounds of the blood remain normally high. Blood calcium remains practically normal.5. Vitamine deficiency of the diets had no adverse effect. Exogenous requirements of cattle for vitamines A, B, and C are so low that they are covered by a few pounds of poor quality roughage, and therefore do not enter into consideration under any natural system of cattle rearing.

Description: Workers on Virus Diseases of the Potato labour under a disadvantage inasmuch as they are frequently confronted with the difficulty of obtaining positive results of infection in one and the same season. Moreover, tubers resulting from a plant which has been artificially infected in one season, retain the secret of the success or otherwise of the operation until adult plants have been grown from them in the succeeding year. Any method which will sensibly curtail this long waiting period is welcome. As long ago as 1788, Joseph Webb, writing on “Curl” in potatoes, recommended that a sample of the seed-tubers intended for planting in the following season should be planted in a hot-bed before Christmas, and that if 2 per cent, or more of the plants exhibited Curl, the stock should be destroyed.

Description: An account is given of an investigation of the alga-flora of four English soils by means of dilution cultures of freshly gathered samples of soil from the top, second, fourth, sixth and twelfth inch depths and from the top 6 in. mixed. A counting method is described applicable to the green algae and diatoms, by means of which it is shown that these algae are distributed throughout the top 12 in. of soil, though at the sixth and twelfth inch depths they are considerably less numerous than nearer the surface. At the fourth inch depth the numbers of individuals are not significantly smaller than on the surface and may be even greater.The unmanured plot of Broadbalk wheat field was found to contain the same main species as the adjacent farmyard manure plot but was poorer in numbers of individuate. Thirty-five species are described from each plot; they seem to be divisible into two groups, the true soil forms and casual species. Of the true soil forms some grow equally well on the surface and in the lower layers, whereas others are more numerous on the surface than within the soil. The same main types were also obtained from Barnfield and from a cottage garden, but the blue-green species were less conspicuous in both of these soils.Experimental evidence is given to show that many of the algae of the soil exist in a vegetative condition rather than a resting condition. Biological notes are made on some of the more important or interesting soil species.

Description: Dried spent hops possess a high absorptive capacity, and attention is drawn to its use as a “filler” to absorb such by-products as molasses and treacle.The material possesses a high crude protein value and its ether extract is very high for a fibrous food, while the amount of crude fibre is the same as in good meadow hay. There is a high percentage of mineral matter present.The digestibility of the material has been determined by feeding with hay chaff and linseed cake meal to three sheep. The spent hops were not readily eaten and could only be included in a ration in an amount equal to one-seventh of the dry weight of the total ration.Its digestibility is low, a fifth of the crude protein and the nitrogenfree extractives, one-half of the ether extract, one-twentieth of the crude fibre and one-fifth of the total organic matter only being digestible. The production starch equivalent was 24.5.

Description: This quarry is situated three-quarters of a mile north-east of Arundel Castle on the west bank of the River Arun.