ALBERT

Description: 1. The addition of casein to the mixed lime sulphur-lead arsenate spray causes:(a) an increase in the amount of soluble arsenic formed on the decomposition of the spray,(b) no change in the reactions of the polysulphide sulphur.2. The addition of lime to the spray:(a) decreases the formation of soluble arsenical compounds,(b) reduces the fungicidal value of the spray owing to its reaction with the sulphur liberated from the calcium sulphide.3. The addition of lime-casein to the mixed spray is influenced by the composition of the lime-casein.If much free lime is present:(a) the formation of soluble arsenic is dependent on external conditions which in certain cases tend to decrease the amount of soluble arsenic formed,(b) the fungicidal value of the spray is reduced as in 2 (b).If slight excess of lime is present, or if the sample has badly carbonated:(a) the amount of soluble arsenic is increased,(b) there is little effect on the reaction of the polysulphide sulphur.4. The addition of gelatine to the spray:(a) increases the formation of soluble arsenic,(b) has no effect on the reaction of the calcium sulphide.5. The rate of decomposition of the mixed spray is retarded by the addition of casein, lime, lime-casein and gelatine.

Description: 1. An improved and simplified laboratory method of measuring the electrical conductivity of soils is described and measurements recorded for diverse soil samples.2. The results for ignited soil lead to certain interesting confirmations of the capillary theory of an ideal soil.3. The results for soils generally indicate a sufficiently simple connection between conductivity and moisture for this property to be made the basis of soil moisture determinations.4. Certain clays were found to form a class apart, and must be regarded as exceptions to the general statement in (3) owing to the more complex nature of the moisture-conductivity relationship.

Description: The variations in Hutchinson-MacLennan “lime requirement” with the amount of soil and calcium bicarbonate solution are shown to be connected with the buffer action of the soil. Indirect titration curves can be derived from the calcium bicarbonate results, and show a systematic divergence from the direct electrometric titration curves, owing to the variable calcium concentration of the final bicarbonate solutions. In the presence of calcium chloride both methods show lower pH values for a given base absorption and yield almost identical titration curves. The Hutchinson-MacLennan “lime requirement” is always less than the equivalent of the amount of calcium hydroxide necessary to give a neutral suspension in the electrometric titrations. The calcium bicarbonate solutions at equilibrium are always more acid than pH 6·2, but the “salt effect” tends to give results corresponding to a somewhat higher degree of neutralisation. “Lime requirements” should be obtained by interpolation to some arbitrary concentration, and an empirical relationship is given by which the interpolation may be made from a single determination. The Hutchinson-MacLennan method can give no indication of the intensity of soil acidity, but serves to estimate the amount of lime necessary to give a considerable reduction of acidity.

Description: The reactions of the unmanured and the limed and unlimed portions of the sulphate of ammonia plots on Eothamsted Park Grass and Woburn barley fields change steadily with increasing depth, and at 36 inches still show the same relations as in the surface soil. The difference in pH values between the limed and unlimed portions of the Rothamsted soil is substantially constant at all depths down to 36 inches. The reaction of the subsoil plays an important part in determining the effect of liming. The subsoils from the sulphate of ammonia plots at both centres are highly flocculated. Mixtures of 1 part of soil with 5 parts of water exhibit complete flocculation in the case of all samples below 9 inches and the velocity of sedimentation decreases and the volume of the final sediment increases regularly and markedly with the depth. Such changes in soil texture probably constitute important factors in the action of a high surface acidity.

Description: The Rothamsted Park Grass and Woburn Barley soils are almost all acid. Ammonium sulphate has caused a considerable increase in acidity, and sodium nitrate a slight decrease. Mineral manures have but little effect, and potassium sulphate has slightly increased trie acidity of the subsoil below the more acid plots. There is some evidence that the pH value 3·8 represents a maximum acidity in the Rothamsted soil. The change in pH value as a result of liming is less than that shown in the laboratory, owing in part to the subsoil acidity.

Description: The mechanical properties of soils which are concerned in ploughing are considered under the three heads:(1) Soil cohesion.(2) Soil plasticity.(3) Surface friction between soil and metal.In each case methods of measurements are discussed and experimental curves are given for representative soils over the whole moisture range with which the practical agriculturist is concerned.In the case of cohesion Atterberg's method of measurement is followed. A certain difference in character between his results and the author's is discussed.A new technique is described for measuring one of the plastic constants, which is specially adapted to clays, and throws fresh light on their physical characteristics.The measurements on soil friction open up a fresh subject, and promise to provide a sensitive means of investigating soil-water relationships from a new angle.

Description: A study has been made of the intensity of the forces binding soil particles together, when the soil has been previously subjected to treatments simulating various field conditions, and certain laboratory processes connected with physical, chemical and biological investigations.The technique adopted consisted in shaking soil with water under reproducible conditions, allowing the mixture to stand for 24 hours, and then determining the concentration of soil in the top 8·5 cm. of the suspension. This concentration was expressed as a percentage of the original concentration of the soil, and the value thus obtained was called the dispersion factor of the soil under the given conditions of treatment.

Description: Canada's western prairies, lying within the confines of the provinces of Manitoba, Saskatchewan and Alberta, are generally recognised as comprising one of the largest and most important agricultural areas on the American continent. The immense acreage of their arable lands, the great depth and high fertility of their soils and the unexcelled quality of their wheat, have made them widely and favourably known throughout the civilised world. As yet but sparsely settled they will for many years offer a large and attractive field for agricultural occupation and development.

Description: The agricultural conception, yield, piquantly clear to farmers, has evaded statistical analysis and confounded plant physiology. It may be defined for cereals as the average weight of grain produced per unit area. Grain is an end-product of the operation throughout the plant's life, of all its vital processes. Yield therefore, in some complex way, must reflect the working of these processes. An analysis of yield would simplify the testing of new plant forms and regularise the selection of parents in hybridising. Fundamentally this analysis should comprise the identification of the vital processes of the plant, the effects upon them of environmental factors, and their relationship to grain production. At present even to speculate upon the making of such an analysis would be mere pedantry. Nothing but an algebraic analysis is practicable.

Description: The secretions of the cervix are of interest because of the changes that occur in them during the oestrous cycle and during pregnancy. It is probable that these changes have an efEect in assisting or hindering the ascent of the spermatozoa to the Fallopian tubes after their deposition in the vagina.

Description: 1. The value of lime-sulphur, liver of sulphur and ammonium polysulphide depending upon the amount of polysulphides that they contain, there is need for an exact method for the estimation of their content of polysulphide sulphur.2. The method of R. M. Chapin has been tested under a variety of conditions and, after making slight modifications to increase rapidity and ease of manipulation, it is recommended as being sufficiently accurate for the purpose in view.

Description: In the course of an investigation on the nitrification process in soils a series of pot experiments was set up to compare the manurial actions of some typical organic nitrogen compounds. The laboratory work was interrupted at an early stage; the results of the pot experiments are briefly described in this note.

Description: It has long been recognised that in plants the susceptibility to disease is influenced to a considerable extent by the manuring practice followed. Ill-balanced fertiliser mixtures decrease the capacity for disease resistance; this has been frequently observed after the application of excessive amounts of nitrogenous manures, and has been demonstrated at Rothamsted and Woburn, where wheat and barley suffered most severely from rust and mildew in those plots which received excessive quantities of nitrogen; also at Cheshunt, where tomatoes heavily dressed with nitrogenous manures were readily attacked by disease-producing organisms. The effect of applying phosphoric acid has not, apparently, been clearly demonstrated, but it is generally assumed that, by favouring the development of a vigorous root system, its action is beneficial. Experiments at Cheshunt have shown that the use of manures from which potash has been omitted, produced a condition similar to that following the application of excessive amounts of nitrogenous fertiliser, and that the addition of potash tends to increase appreciably the ability of the plant to resist disease.

Description: In Table XII is given a summary of the mean digestion coefficients obtained in the foregoing maize feeding experiments.The figures in Table XII bring out very clearly the effect of preliminary treatment on the digestibility of maize. An inspection of the dry matter digestion coefficients reveals the fact that maize meal possesses the lowest digestibility when fed in the dry condition, a higher value when fed after thorough soaking in water and a higher value still when first submitted to cooking.These facts are in accordance with anticipation; the surprising feature of the results, however, lies in the discovery of the inappreciable extent to which the maize digestibility is raised by soaking or cooking. A relatively low degree of digestibility might justifiably have been anticipated for raw unsoaked maize, since the hard flinty nature of the grain, even after crushing, might render it liable to be excreted in appreciable amount into the faeces without having been much affected by digestive enzymes. This proved by no means to be the case. The effect of thoroughly soaking the grain prior to feeding was merely to raise the digestibility of the maize by 1 per cent, (from 85·9 per cent, to 86·9 per cent.), whilst even efficient cooking only brought about a rise in digestibility from 85·9 to 88·1 per cent., although, as will be noted by reference to an earlier part of this communication, the conditions of the trial were weighted in favour of the cooked meal by using fine meal for cooking and crushed maize for dry-feeding.

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 relative proportions of exchangeable bases in nine soils from the east of Scotland area and the changes effected by dilute chloride solutions have been examined.2. The changes due to N/50 solutions are large, and magnesium is displaced to a greater extent by calcium than by potassium.3. The changes due to N/500 solutions are very small, comparable to what might be expected in manurial practice, and not greater than field sampling error.4. The content of exchangeable bases and their relative proportions, therefore, seem to be fairly permanent for any soil under normal conditions, but vary considerably from soil to soil, and should prove useful as an additional characteristic of soil type as distinguished in the field.

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: An account has been given of an investigation into the seasonal changes in the productivity, botanical and chemical composition, and nutritive value of pasture grass, the work constituting the initial stage of a comprehensive study of the nutritive properties of different types of pasture. The pasture on which the work was carried out was situated on a light sandy soil of low water-retaining capacity; the pasturage was of medium quality.Grazing was imitated by the daily use of a motor-mowing machine, the system of cutting being such as to ensure the whole plot being cut over once per week. The season was divided into ten periods, each period corresponding with the duration of a digestion trial carried out on two wether sheep. The main feature of the weather conditions during the season was the extremely low rainfall during the period from early June to mid-July.The pasture plot results were compared with corresponding results obtained from contiguous plots which were allowed to grow for hay, and from which, after removal of hay, several successive aftermath cuts were taken. The main findings of the investigation are summarised below:Seasonal changes in the botanical composition of the herbage. Although precise and systematic botanical analyses of the herbage of the pasture were not carried out, yet careful surveys made at an early and a late date in the season, together with general observations made during the whole course of the experiment, enabled interesting conclusions to be drawn in respect of the seasonal activity and persistency of the different species of grasses in the sward. During the spring season, Bromus mollis, Lolium perenne, Poa annua and Poa trivialis accounted for almost 80 per cent, of the herbage.

Description: (1) The addition of basic slag to moist base-unsaturated soils, under laboratory conditions, causes an increase in their content of exchangeable calcium, degree of saturation, pH, and the amount of calcium soluble in an aqueous solution of carbon dioxide.(2) Slag seems to be almost as effective as calcium carbonate or lime in increasing the exchangeable calcium and the degree of saturation of soils, but its action on pH is not so marked.(3) The effect of dressings of slag on the lime status of soils from experimental plots is still evident after eight years.(4) The exchangeable calcium of samples of soil taken from the same fields after an interval of six years shows a considerable fall due to leaching.(5) It is suggested that the addition of low grade basic slag to unsaturated soils may tend to maintain or improve their lime status and will, to some extent, compensate for the loss of calcium due to drainage and crops.

Description: The addition of aluminium salts to culture solutions and to soils will bring about certain changes; these may be summed up as follows:1. A change in the hydrogen ion concentration, which will vary in amount with the original buffer properties of the solution or the soil.2. A change in the buffer properties of the solution or the soil; the hydrogen in concentration of a culture solution containing an aluminium salt will tend to remain more constant than that of a normal culture solution during the period of growth of the plant, when both start at the same pH value.3. Precipitation of soluble phosphate as aluminium phosphate except in solutions or soils more acid than pH 3·5 to 4·0; this might lead to phosphate starvation in water cultures but would have little or no effect in a soil, where the particles would remain accessible to the plant roots.

Description: Some recent researches on the evaporation of water from soil are reviewed.Experiments on the evaporation of water from a soil paste spread in shallow pans showed that the drying proceeded very irregularly over the soil mass. Considerable portions became almost completely dry whilst other portions remained very wet. There was a rough relationship between the form of the dry patch and the shape of the corresponding evaporation rate curves.An improvement in technique was effected by exposing the soil in thin layers below glass plates. Under these conditions, reproducible results were obtained. Soil and kaolin, but not sand, gave considerable linear portions over the region of decreasing rate of evaporation. Tests on soil exposed as central discs, or peripheral rings, and on partially covered full plates, showed that, owing to the type of air currents set up, the drying was largely confined to the outer edges during the early stages.

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: The question of the composition of sugar beet tops and their utilisation for feeding purposes has been dealt with in a recent publication (l). The purpose of the present communication is to record the results of investigations into the problem of the preservation of sugar beet tops by the method of ensilage. The account falls naturally under four headings:I. Ensilage of sugar beet tops alone.II. Ensilage of sugar beet tops mixed with wheat chaff.III. Ensilage of sugar beet tops mixed with wet sugar beet pulp.IV. Nutritive value, as determined by digestion trials on sheep, of the silage obtained from the mixture of tops and pulp.

Description: The figures analysed in the subsequent pages were obtained (by the kind permission and help of Prof. S. Pennington) during the five years, May 1920 to May 1925, from the College Farm dairy cows at University College, Reading, and before proceeding, a few notes on the herd and its management are desirable.The herd is small (14–18 animals), and was established in 1908 by purchasing non-pedigree Dairy Shorthorn heifers which have since been “graded up” by the use of Pedigree Dairy Shorthorn bulls. The cows are typical Dairy Shorthorns, of a fairly large size, and the degree of fatness normally maintained might be described as good thriving condition, and probably better condition than average dairy cows.

Description: The calcium arsenate-lime-lime sulphur spray has been studied in the laboratory and from the results so obtained it is inferred(1) That the formation of a stable tricalcium arsenate by precipitation from aqueous solution is improbable. The interaction of calcium hydroxide and dicalcium arsenate results in the formation of a continuous series of basic calcium arsenates which are hydrolysed in aqueous suspension.(2) That through the formation of such basic calcium arsenates the addition of lime to dicalcium arsenate reduces the amount of arsenic in solution. This reduction is temporary and on exposure to atmospheric carbon dioxide the original solubility of the dicalcium arsenate is restored. The concentration of soluble arsenic in the dicalcium arsenatelime spray will not be as great as in the dicalcium arsenate spray and the risk of spray injury with the dicalcium arsenate spray is therefore reduced when lime is added.(3) The concentration of soluble arsenic in the dicalcium arsenate and lime spray is reduced by the admixture of lime sulphur with a corresponding reduction of the risk of foliage injury.(4) The precipitation of sulphur from the calcium polysulphides of the lime sulphur is unaffected by the addition of dicalcium arsenate. The addition of lime may result in a diminution of the amount of sulphur so precipitated but such a reaction is dependent on the rate of carbonation of the free lime on the leaf surface. The fungicidal activity due to the calcium polysulphides is therefore unaffected by the addition of dicalcium arsenate but may be adversely influenced if excess of calcium hydroxide be present.

Description: In the Journal of Agricultural Science for October 1921, Dr J. W. Capstick described a calorimeter large enough to take a full-grown pig or a small bullock. This apparatus was in regular use up to the end of 1923 and proved, on the whole, quite satisfactory.

Description: The investigations described in the present paper are based on the records of the dairy herd at the farm of the University College of North Wales, at Aber near Bangor. The results obtained will have a more definite significance if some account is given of the nature and management of that herd.The Bangor provincial area, including the four Northern Counties of Wales, is roughly divided into Welsh Black and Shorthorn country by the Conway River. Most of the cattle in Anglesey and Caernarvonshire are of Welsh Black type, and the ordinary non-pedigree dual purpose type of Shorthorn predominates in Denbighshire and Flintshire.

Description: 1. Tubers obtained from secondary leaf-roll plants have a lower dry matter content than tubers from healthy plants. The percentage of nitrogen in the dry matter is appreciably higher in the former than in the latter. The difference in dry matter content is sufficiently large in many varieties to characterise leaf-roll tubers. Seventeen varieties were examined.2. The rate at which the nutrient materials are removed by the young plants from leaf-roll mother tubers is much slower than in the case of plants from healthy mother tubers. This may be a cause of the stunting characteristic of leaf-roll plants.3. When there is any doubt as to the diagnosis of secondary leaf-roll by the usual symptoms, a determination of the dry matter in the mother tuber two to three months after planting, would serve as a further diagnostic character.

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: In a former number of this Journal (1), there appeared a report on the mechanical analysis of soils by this sub-committee of the Agricultural Education Association. The report contained proposals for certain modifications of the earlier A.E.A. (1906) method, of which the most important were the introduction of hydrogen peroxide as a dispersive agent in the preliminary treatment, the use of the pipette method for the actual mechanical analysis, and the abolition of the fine gravel (3 mm.–1 mm.) fraction. This report was officially adopted by the A.E.A. and the method of mechanical analysis therein proposed was accepted as the new standard to replace the 1906 method. The full details were published in the Journal of the Association (2).

Description: The study has comprised a detailed analysis of twelve samples of soil, ten of which were samples of typical peat soils, the other two being samples of normal soils. The degree of humification of the organic matter of the samples varied, that in the wet peats being high and low in the dry peats.Extracts of the soil were obtained by the use of boiling hydrogen peroxide, 20 per cent, hydrochloric acid and 2·5 per cent, caustic potash.Hydrogen peroxide extracted roughly 70–80 per cent, of the soil nitrogen, 60–70 per cent, of this soluble nitrogen appearing as ammonia through the oxidising effects of the reagent. The nitrogen compounds of wet peats were more easily oxidisable to ammonia.

Description: 1. The capillary pull of an ideal soil has been determined by measuring the maximum hydrostatic pressure (H) sustainable by a liquid surface formed, amongst an assemblage of uniform spheres of mean diameter 0·0374 cm. (2a). It has been found that using liquids of low surface tension like benzene to avoid contamination, the constant K in the equation Hgp = KT/2a has the weighted value 9·5.2. Values of K for single apertures between three and four spheres in contact have been determined, using steel spheres of a diameter ⅛ in. and benzene. It is found that K does not vary rapidly for four spheres and has a value between 9 and 10 for apertures in which the ratio of breadth to length varies between 1·0 and 0·4.3. The equivalent capillary tube is the circular or elliptic cylinder touching the spheres forming the aperture. This assumption gives values of K in fair agreement with observation.4. The value of K is practically independent of variations of pore-space ranging from 36 per cent, to 40 per cent, such as usually occur in ordinary packing.

Description: A new and improved type of dynamometer is described which by a simple interchange of parts can be used with the same percentage accuracy for all types of work from the lightest to the heaviest.The instrument consists of (a) an hydraulic link weighing 16 1b. and placed in the hitch, (b) a recording mechanism weighing 15 lb. carried on any convenient part of the implement, and (c) a control box weighing 4 lb. carried by the operator. When packed in a stout box for transit and with all accessories the total weight is less than 100 lb. The instrument is of robust construction and has a minimum number of moving parts. Adjustments for stylus pressure, etc., are provided, but the necessity for using them hardly ever arises.The instrument operates by recording the amount of movement in a Bourdon tube filled with oil and connected by narrow bore copper tubing to the oil in the hydraulic link.

Description: 1. A thermophilic organism which destroys cellulose at 65° C. has been isolated in pure culture.2. The organism is motile, gram negative, forms spores in the swollen end, stains well with carbol fuchsin, poorly with methylene blue.3. After growth on media without cellulose the organism is unable to ferment cellulose.4. The range of fermentation is from 43° C. to 65° C. The organism lives at 38° C. and 72° C. but does not ferment at these temperatures.5. The spores are very resistant to heat and withstand 115° C. for 35 minutes.6. Heating the spores to 100° C. for 5 to 10 minutes causes an increased rate of germination.7. Carbohydrates fermented: cellulose, starch, raffinose, sucrose, maltose, lactose, mannose, galactose, fructose, glucose, xylose and arabinose.8. Organic nitrogen is necessary for the fermentation, and peptone is the best source.9. The products from cellulose are: acetic acid, small amounts of butyric acid, ethyl alcohol, carbon dioxide and hydrogen. The amount of cellulose destroyed in a 1 to 5 per cent, suspension varies from 70 to 95 per cent. Of the cellulose destroyed, 50 to 55 per cent, is regained as acetic acid, 5 to 25 per cent. as ethyl alcohol and the rest as small amounts of butyric acid, carbon dioxide, hydrogen, and pigment. The pigment is a fatty substance soluble in ether.

Description: During the past five years many appeals for assistance have been received at this Institute from cheesemakers in various parts of the country, who from time to time have found, themselves unable to secure satisfactory coagulation of their milk by rennet by reason of some abnormality which is not patent to the eye.Difficulties are also encountered in the liquid milk trade from causes which appear to resemble those which trouble the cheesemaker.In view of the necessity for detecting milk such as this, use has been made of di-brom-ortho-cresol-sulphon-phthalein or brom cresol purple, which indicates colorimetrically the reaction or hydrogen-ion concentration of milk, and provides a starting point for the further investigation of those samples of which the reaction is abnormal.

Description: 1. The formation of colloidal CaHPO4 by the interaction of CaCl2 and Na2HPO4 in the presence of neutral casemates has been demonstrated.2. The colloidal CaHPO4 is shown to be non-diffusible across a membrane of cellophane.3. A theory is outlined which will account for the secretion of the high concentrations of calcium and phosphorus in milk from the low concentrations of these elements in the blood.

Description: An unknown phosphorus fraction previously recorded by the authors as frequently present in calf blood, is shown to be nucleoprotein and due to the presence of precursors of fully mature erythrocytes. The same fraction may also appear in small amounts in human blood and in horse blood, and always occurs in very large amount in the nucleated erythrocytes of birds.

Description: In the account of “Pining” in sheep given by McGowan(1) there are so many points of similarity, both in the symptoms and in the general environmental conditions under which the disease is developed, with the disease known in New Zealand as “Bush-sickness,” as to suggest that these two diseases may be of a similar nature.

Description: On the arid, sparse, phosphorus deficient pasture of the Vryburg district of the Cape Province, grading up of scrub cattle, by combining the introduction of pure bred bulls with the feeding of bone meal to the cows, is attended with great success so far as shown by the first crossing. Remarkable differences in favour of the mineral supplement are shown, in respect to reduced mortality incidence, increased fertility of cows, and superior development of calves.

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. The value of the knowledge of the saturation capacity of a soil as an aid in its characterisation and classification is briefly stated.2. A short account is given of the more important methods in use for determination of saturation capacity.3. The theory underlying the method of Page and Williams, and the possible defects of the method are discussed.4. The results of an investigation of this method lead to the following conclusions:(a) Leaching the mixture of soil and calcium carbonate to 2 litres is in sufficient to displace from the soil all its exchangeable bases.(b) In view of this, it is recommended that 3 litres or more of filtrate be obtained, or preferably, the amount of soil employed be reduced to 10 grm.(c) The leaching solution remains in contact with the soil mixture for a period adequate for the normal sodium chloride solution to be saturated with calcium carbonate.(d) The difference in the amount of calcium, derived by solution from the carbonate, in the first and second litres of filtrate, is sufficiently small to be neglected.(e) The tardiness with which the reaction proceeds to completion is probably due to the difficulty experienced in displacing the final amounts of adsorbed ions, rather than to the presence of calcium ions in the leaching solution.(f) The incompleteness of the reaction renders the method of Hissink inaccurate for the calculation of the saturation capacity.(g) The variation in the character of the colloidal material of soils i s to some extent reflected in the value of the ratio of the calcium passing into solution through exchange reactions in the second litre, to that dissolved in this manner by the total volume of filtrate.

Description: 1. Considerable differences were found in the specific conductivities of different soils at any one time of the year, and considerable differences in any one soil at different times of the year, the specific conductivities being highest in March and lowest in June and July. Hence it is only possible to compare different soils when samples of these soils are taken at the same time of the year.2. A relation has been found between the specific conductivities of the soil extracts and the mean weights of lint per plant per row in the case of 2 strains of Ishan cotton. Other data are presented showing that the specific conductivity of a 1 to 5 soil extract is an index of the fertility of the soil.3. It has been found that the specific conductivity of a soil decreases under continuous cultivation. There is evidence that the rate of solution also decreases under the same condition.

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: 1. Digestibility trials with oats, carried out with White Leghorn cockerels, indicate that certain varieties of oats are more suitable as sources of food nutrients for poultry than others.2. In the trials carried out, Grey Winter oats proved more suitable than Black Bountiful or Scotch Potato oats for poultry feeding.3. The suitability of varieties of oats for poultry feeding appears to be linked with the fibre content, and thin husked varieties appear to be most suitable for this purpose.4. Oats do not appear to be very palatable to poultry.

Description: The results of four experiments are described in which twenty-five pigs were fed on a ration containing half a pint of milk. Eighteen were fed on control rations, generally considered to be adequate, and of which in one series dried separated milk was a constitutent.In every case the fresh milk produced an increase in live weight over the controls varying from 8 to 10 per cent. Less dry matter per lb. increase in live weight was consumed by the experimental pigs than by the controls.The returns for half a pint of milk fed per pig daily expressed as pounds live weight gain per gallon of milk fed, were as follows:The higher values in Exps. 2 and 4 may have been due to the fact that the pigs were individually fed but differed in that the milk was mixed with the food in Exp. 2 and fed separately in Exp. 4.

Description: The distribution of salts in the soil is generally related to compactness of the soil profile as judged by the distribution of gypsum, of calcium carbonate aggregates and of soil colour. The relation already established between salt content and fertility is now expressed as a relation between compactness of profile and fertility. The data agree well with geological views as to the origin of this soil. Influences of which the soil profile is the product are also discussed.I am much indebted to Mr G. W. Grabham for practical instruction in field work and for information as to the origin of Gezira soil. I wish also to thank Dr A. F. Joseph for his interest in this work and for facilities placed at my disposal.

Description: In regard to phosphorus partition, the same general relationship holds between the blood of lambs and of the mother ewes, as between the blood of calves and the mother cows. Total phosphorus is about twice as high in lamb blood as in maternal blood, inorganic phosphorus about twice as high, and organic acid-soluble phosphorus about three times as high. A considerable proportion of an acid-insoluble phosphorus fraction, probably nuclein, may be present in the red corpuscles of lamb blood and may even be present in foetal blood. The organic acid-soluble fraction is confined to the corpuscles, both in young blood and adult blood, but i n one case of a six-month calf foetus a small proportion was noted in plasma.

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: A method is described for the determination of the fluorine content of basic slag.The fluorine content and the citric solubility of a number of basic slags are compared.

Description: (1) The results of experiments on the rate of horizontal flow, and on the rate of gain in mass, or kerosene and of water in fine and crumb fractions of certain West Indian colloidal soils, comprising three siliceous soils containing different amounts of calcium carbonate, and two lateritic soils, are described and tabulated.(2) The methods of experimentation employed were those elaborated by Green and Ampt, whose equations were found, however, not to fit the values obtained, as is to be expected.(3) The siliceous soils examined possess relatively high swelling coefficients, and their component particles, when wetted, cohere to a greater or lesser extent, depending on lime content. These properties appear to account for the relatively low rates of permeability to water in these soils. Lateritic soils, on the other hand, possess low swelling coefficients, and low cohesiveness; water percolates through them relatively very rapidly.

Description: Measurements are recorded of soil resistance to ploughing, taken with a view to testing the uniformity of a soil over a single field. The results have been examined for significance and indicate large variations over short distances. The differences have been represented by means of isodyne contours (i.e. lines of equal drawbar pull), drawn on a map.The importance is emphasised of assuming and allowing for such variations before drawing conclusions from the drawbar pull recorded by different implements.Preliminary work is described showing that the variations are correlated with clay content and also with the growth of a crop in its early stages.

Description: In a former paper (1) it was shown by solubility curves and pot experiments that the Wagner citric acid method is a satisfactory means of evaluating basic slags but is unsatisfactory for mineral phosphates.

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: With the aid of a careful technique a critical investigation has been made of the Hygroscopic Coefficient of soil at five temperatures, ranging from 15° C. to 35·6° C. It has been shown that (1) the customary 12–24 hours' period used by previous workers is much too short to give any approach to final values; (2) at the lower temperatures all except very light soils continue to take up water almost indefinitely, and it is not possible to extrapolate to an approximate final value; (3) these final values decrease with increasing temperature but in the early stages the rate of moisture absorption increases with increasing temperature; (4) the disputes as to whether the Hygroscopic Coefficient increased or decreased with temperature were due to the unrecognised operation of the effects detailed in (1) and (3) above.

Description: A series of upwards of 6000 matings of goats has been arranged according t o the month of service and correlated with temperature and rainfall.The maximum of reproduction is found to be in October, and the minimum in May.A cool summer produces early oestrus while a hot one has the opposite effect. The August temperature is of paramount importance in this respect.Rainfall had no effect, on the onset of oestrus in the series examined.The hypothesis is advanced that most mammals breed only in the spring and autumn because their body temperature may be too high in summer for follicular development.

Description: For the purposes of this article the “food capacity” is taken to be the amount of total dry matter consumed when the animal is offered as much as it cares to eat. This has been estimated from the results of a variety of experiments collected by the author for the purpose.The evidence quoted shows that the food capacity of steers is subject to a nearly uniform acceleration of 40 lb. per month per month from birth up to the age of 12 or 14 months, after which it remains approximately constant. It cannot therefore bear any simple relation to the live weight of the animal.In the case of steers the average constant rate of consumption was about 18 lb. of total dry matter, per head, per day, throughout the period from 1 to 4 years of age; in the case of milk cows it is probably about twice as great, viz. from 30 to 40 lb.The food capacity of steers has been much exaggerated by various scientific writers. In Kellner's tables it seems to be implied that the capacity varies as the live weight and that it may be as much as 64 lb. per head per day, i.e. 3½ times as much as was found in the experiments under review.

Description: The flooding with sea-water of land around the Humber in 1921 spoilt a considerable area of arable land.The effects of the flooding, which consisted chiefly in an entire destruction of the tilth of the soil, are described, and compared with the recorded effects of similar floods in Holland and in Essex.The results of an examination of the exchangeable bases in the flooded soil are considered in the light of modern work on the relation between the nature of the exchangeable bases in the soil and its physical condition. It is shown that the observed effects can be explained by replacement of a considerable proportion of the exchangeable calcium of the soil by sodium.Dutch experience on the reclamation of flooded soils is discussed. It is shown that in the first few years after flooding the land should be cultivated as little as possible.The use of lime or gypsum for the treatment of flooded soils, in order to hasten the restitution of calcium to the clay in place of sodium, is discussed. From an examination of the soil from plots which had been treated with these materials it is shown that although both produced in some degree the desired effect chemically, the action did not proceed far enough in 12 months to produce a noticeable improvement in the tilth.It may be possible under favourable conditions to grow certain arable crops on flooded land, among which crucifers appear to be specially suitable.However, the most satisfactory and promising means of hastening the recovery of tilth and fertility by flooded land appears to be the establishment of a ley of lucerne, clover, or “seeds” which can be left down for several years.

Description: Two sets of records, for Light and Heavy Horses respectively, have been analysed statistically, with the object of studying some of the factors which affect the percentage of foals left by a stallion in a service season.It has been found that the stallion himself is one factor, in that each individual’s percentage returns, in successive seasons, tend towards a constant figure; although there is every gradation, and even considerable variation from year to year, there are definitely good and bad “getters” of foals.A stallion's fertility varies according to the district of the country in which he stands or travels, being higher in the north and west of England and Wales than in the south and east, and very low in Scotland.In moderation, frequent use does not impair a stallion's fertility; there is, in fact, some (insignificant) evidence that the more mares he serves, the greater the proportion of foals he leaves.There is a slight tendency for a stallion's fertility to rise from the time he is 3 years old till he is 13 years old—this result may, though, easily be due to chance; on the other hand it is quite clear that fertility declines after the age of 16 years, and this occurs over the whole range, and is not caused by a certain number becoming absolutely sterile.

Description: Although the infertility of the subsoil in humid, semi-arid and arid regions has received much attention from investigators in Europe and America, in South Africa, as far as the writer is aware, no such work has been done.

Description: A physical form of “ropiness” in milk has been described and shown to be due to the formation of thin films of casein and (or) lactalbumin at the milk-air interface.The “ropes” are a form of the “mechanical surface aggregates” of Ramsden and may occur on appropriate surfaces, such as ordinary farm coolers whenever the rate of flow, the temperature and the acidity conditions are favourable.A modification of Ramsden’s method demonstrating the formation of mechanical surface aggregates, in an hitherto unobserved form, has been described, viz. horizontal glass tubes in parallel which are especially suitable for opaque fluids.The condition appears to be identical with that described by Aekma and Brouwer(2) who showed the occurrence of corpuscles in milk after violent agitation. These corpuscles probably consist of thin films of solid protein which as in the cases described by the author have formed at the interfaces of air bubbles and milk.The phenomenon has been shown to be of importance in handling dilutions of milk in the course of bacterial enumeration.

Description: 1. An examination is made of some aspects of the replacement or exchange of bases by ammonium chloride solution, in a soil about which considerable information had been acquired regarding its physical, chemical, and mineralogical constitution, namely, the soil of Craibstone Experiment Farm, Aberdeen. Certain data in this connection are given.2. The “course of replacement” of calcium by ammonia, by successive applications of equal amounts of a normal solution of ammonium chloride is examined, according to the method of Gedroiz. Comparison is made between the results got for the Craibstone soil and those for a tshernoziem soil examined by Gedroiz. By means of graphs the agreement between the two soils as to the “course of replacement” is shown, and a distinction made between easily extractable calcium, and that more slowly removed in solution. The “course of replacement” of potassium and magnesium in the Craibstone soil is also examined.3. The presence of silicon, aluminium, iron and manganese is also noted in the extracts.4. The soil is also examined for “Total Exchangeable Bases” by extraction with normal ammonium chloride, according to the method of Hissink, with minor modifications.5. Exchangeable aluminium, iron, calcium, magnesium, manganese, potassium and sodium were found and in addition silicon was present in the extracts.6. The question of the presence of silicon, aluminium, iron and manganese in measurable amounts in extracts from acid soils is discussed.7. The relative proportions of exchangeable divalent and monovalent bases found were as follows. Calcium 85·02 per cent., magnesium 8·11 per cent., potassium 2·18 per cent., sodium 4·68 per cent. These results are in general agreement with those found for acid soils.

Description: An account has been given of the different methods adopted for extracting protein material from the juice of the mangold root and subsequent purification of the crude material.Three samples of protein have been isolated in different ways and their distribution of nitrogen determined by the van Slyke method.Two globulins and an albumin have been extracted from mangold seed, the two globulins being isolated very pure and an elementary analysis done. These two proteins differed in sulphur and nitrogen contents and different physical properties justified their being looked on as two distinct proteins.Distributions of nitrogen by the van Slyke method revealed differences in the globulins, especially in their contents of arginine and histidine.The similarity between the root and the seed proteins has been pointed out, and the root protein has been compared with animal proteins.

Description: (1) The herbage of the hill pastures in Great Britain is, in general, markedly poorer than that of the cultivated pastures in respect to silica-free ash, and each of the individual ash constituents, with the exception of sodium. It is also poorer, but to a less extent, in nitrogen.(2) The percentage of silica-free ash in the “not eaten” grass from the hill pastures is only approximately 50 percent of that in the “eaten” grass. This deficiency is fairly uniformly distributed over the ash constituents with the possible exception of sodium.(3) Despite these marked differences in the mineral content of the different types of pasture, there is very little difference in their caloric value as calculated by the method indicated.(4) Wherever sheep have a free choice in grazing they appear to eat, by preference, that herbage which contains the higher percentage of mineral ingredients.

Description: In human society, density of population is marked by striking variations. With these are associated geographic, social, and economic differences. Among the plant populations of our fields occur gradations of spacing or density which, by broad analogy, suggest problems akin to those arising from density differences in human populations. It is necessary to do no more than walk the length of one of the drill rows in a field of young corn to appreciate the general situation. The facts are patent some five weeks after sowing when the emergence of the seedlings is almost completed. Side by side with a foot length of drill in which are thirty plants may be another foot with only three. Complete gaps of 2 feet or more are to be found in places: in others the plants are almost too numerous to count. In every field of corn, even at this early stage, the density or closeness of the plants in the drills is extremely irregular. As the season advances various influences induce irregular reductions in the number of plants. Vermin and disease take sporadic toll. Competition between plant and plant with death or effective disablement of the weaker has some effect. Its intensity at any point is mainly determined by the density or closeness of the plants. By May, for winter corn, a static condition has generally been reached. Plants living then are likely to contribute grain and straw to the harvest. Among these survivors are great differences in spacing. This may be readily appreciated by uplifting and counting the roots in sample 1-foot lengths of drill on a stubble field.

Description: 1. Sampling of single roots of swedes by means of cores is subject to errors of various kinds, of which one, due to the asymmetrical growth of the root in a north-south direction, has previously been overlooked. Cores should be taken horizontally in a north-south direction.2. In the case of plants left standing in the field there is a marked decrease in dry matter content during winter and spring; this is presumably due to movement of food-material from the root into the developing flowering shoot. A detailed study of the metabolism of the swede during the winter is urgently needed, if only for the practical purpose of determining the “metabolic turning-point,” which is the ideal time at which to determine potential dry matter content.3. The fresh weight of a core is a function of the weight of the whole root (except in Tankard swedes).4. There is a well-marked negative correlation (autumn – ·66, spring – ·51) between dry matter content and fresh weight of core, and hence between dry matter content and size of root.5. For one pair of strains of common parentage clear evidence of the inheritance of dry matter content has been obtained. In other instances the figures are inconclusive.

Description: 1. Evidence is produced to show that the free water in a soil is 21.2. Wilsdon's modification of the Briggs-Shantz equation is discussed, viz., M = xH + 21, in which x = the vesicular coefficient. From this equation the vesicular coefficient of any soil can be found from the values of M and H.3. The values thus obtained agree for clay soils with those found by Hardy's method from the moisture at the point of maximum plasticity.4. The vesicular coefficient of a soil is greater than that of its subsoil.5. The total bound water = (M – 21), and the vesicular water = M – (21 + H). The vesicular water expressed as a percentage of the plastic soil is equal to the cubical shrinkage coefficient.

Description: In the summer of 1923, the Agricultural Education Association appointed a sub-committee to report on the present position with regard to the mechanical analysis of soils. This committee has now reported to the Association, which has adopted its recommendation that the former Agricultural Education Association method(1) of sedimentation in a beaker shall be replaced by one depending on the depth concentration relationship in a settling suspension. The reasons for this recommendation and the experimental work on which it was based will be of interest and use to soil workers generally. The salient features of the report have therefore been presented in the present paper, and an appendix of methods has been added. The full details of the official method will be published in Agricultural Progress, the journal of the Agricultural Education Association.

Description: In an earlier communication on this subject(1), the writers arrived at the conclusion that the main reason for the comparative failure of attempts to grow maize as a silage crop in this country was due in large measure to the general use of the late maturing variety, American Horse Tooth. It was predicted that success would probably depend on discovering a variety of maize which is able to reach the desirable stage of maturity under English conditions before being cut for the silo. Preliminary trials had indicated that the necessary qualities might be found in certain varieties like Saltzer's North Dakota, Longfellow, Compton's Early and White Cap, all of which mature at least a month before American Horse Tooth.

Description: In the course of investigations into the cause of an obscure pathological condition of the tea bush, it became necessary to make pH determinations of certain soils. Electrometric apparatus and a suitable centrifuge for clearing the solutions were not available. Considerable difficulty was experienced in making the determinations with accuracy by indicator methods owing to two causes. First, the turbidity of the soil solutions made comparison with standard buffer solutions somewhat difficult; secondly, the colours developed in the soil and buffer solutions with some indicators were different in hue, as distinct from shade or tint. This rendered exact matching quite impossible. The latter difficulties also arose when the drop ratio method was used instead of standard buffer solutions. The errors resulting from these causes were believed to be unduly large, and it was felt that greater accuracy would be attained if these difficulties could be overcome.

Description: 1. The interaction of physical conditions of the soil and the establishment of plant together with its subsequent growth and yield have been studied for wheat and swedes on a variable piece of land, maintained as a uniformity trial.2. Ploughing draught was taken as a criterion of the physical condition of the soil and various simple measurements on the crop were made from time to time during growth.3. The establishment of wheat showed substantial negative correlations with ploughing draught but the correlations between ploughing draught and the performance of the plant diminished as growth progressed. This was shown to be the result of the overwhelming importance of the spacing factor operating beneficially on plots where the plant was abnormally poor. The effect of this factor is traced step by step.4. Swedes differing from wheat in almost every detail of cultivation and growth, cycle showed no correlation between soil conditions and germination or between the various growth stages and physical soil conditions. The highest significant correlation was between the number of roots per plot after singling and ploughing draught and an explanation of this is given.5. There was a significant but only moderate correlation between the yields of the two crops.

Description: 1. A historical review of the dye adsorption method for the estimation of soil colloids is presented, and the method is criticised chiefly from the point of view of the isoelectric theory.2. A procedure for the detection of hydrous alumina in soils is described, involving the demonstration of the isoelectrio point of hydrous alumina by means of preferential dye adsorption in suspensions of various pH values.3. Satisfactory results were obtained with a mixture of acidic Biebrich Scarlet and basic Iodine Green. The former is adsorbed by hydrous alumina only on the acid side of its isoelectric point, and the latter only on the alkaline side.4. The characteristics of an ideal dye for use in studies such as those described are tabulated.5. The applicability of the mixture of dye-stuffs finally selected is demonstrated for a series of soils of varying basic ratio, and including examples of lateritic soils and clays.

Description: The question of the effect of iodine manuring on the iodine content of plants has recently assumed considerable importance in view of the use of iodine as a cure and preventive of simple goitre. Whether the theory that goitre is due to deficiency of iodine be correct or not, it appears to be well established that small doses of iodine act both as a cure and a preventive of enlargements of the thyroid. It has therefore been suggested that a simple and effective method of general prophylaxis, in areas where goitre is at present endemic, might be found in increasing the iodine content of foodstuffs such as milk and eggs, by administration of iodine, and of plants by iodine manuring.

Description: 1. The soil temperatures in Egypt at a number of depths have been recorded by means of continuous recording thermometers. In general, the records show that the amplitude of the temperature wave at the surface of the soil is considerably greater than the air temperature wave. There is, however, a considerable damping of the wave with depth, no daily variation in temperature being observed at a depth of 100 cm.2. No definite relation between the air and soil temperatures could be traced. The maximum air temperature was recorded in May and the maximum soil temperature in July.3. The amplitude of the temperature wave decreases with increase in depth. The decrease in amplitude of the soil temperature wave is not regular owing to variations in the physical properties of the soil layers. Between any two depths, the ratio of the amplitudes of the temperature waves is constant throughout the year. The amplitude of the soil temperature wave bears no relation to the amplitude of the air temperature wave.4. The time of maximum temperature at the soil surface is constant throughout the year at 1 p.m. The times of maximum temperature at depths below the surface lag behind the time of surface maximum, but they are constant throughout the year. When plotted against depth, the times of maximum at the various soil depths lie on a straight line.

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.