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: 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 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. 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: 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: 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: The facts and considerations set out above provide the information necessary to enable an intelligent pig-keeper to compute on a logical and scientific basis a series of rations which from the energy point of view will produce any desired rate of live weight increase within the capacity of his animals. It is however necessary to make the reservation that the data apply strictly only to pigs of the Large White breed kept under good conditions and liberally fed.It should also be noted that the method can only be applied to animals of known age and weight.The method is applied as follows:1. From the age of the animals read off from the basal metabolism chart, Fig. 1, the intensity of the basal metabolism per square metre per hour.2. From the live weight—surface chart, Fig. 2—read off the surface area in square metres corresponding to the animal's live weight.3. Multiply the basal metabolism per square metre per hour by the area of the animal's surface in square metres. The product multiplied by 24 gives the basal metabolism of the animal per day.4. To get the practical maintenance requirement add to the basal metabolism per day 1000 calories to allow for an average amount of muscular effort.5. Decide the growth rate in pounds of live weight increase per day at which it is desired to aim. The growth rate curve, Fig. 4, will help in assessing this figure.6. Read off from Fig. 3 the calorie value per lb. of live weight increase corresponding to the live weight of the animals under consideration, and multiply the figure there found by the desired live weight increase in lb. per day. This will give the productive ration in calories per day.7. The total ration is then found by adding together the maintenance requirement estimated in 4 above and the productive ration estimated in 6 above. This gives the total ration in calories of net energy.8. Transform calories of net energy into lb. of meal on the assumption that 1 lb. of meal supplies to the pig 1000 calories, or preferably that 1 lb. of starch equivalent supplies 1500 calories.

Description: 1. The adaptation of plants to resist frost appears to depend on seasonal changes which give the protoplasm stability. A study has been made of the changes occurring in winter wheat plants, of varieties differing widely in winter hardiness, during the fall and winter months.2. By analysing the press-juice as well as the entire tissues at progressive dates, it has been possible to study the distribution of the more important constituents between the physiologically active cell fluids and the relatively inert supporting framework.3. One of the most important changes in the quantitative relations of the various plant constituents is the reduction in moisture content. This takes place to a greater degree in hardy varieties. The resulting concentration of colloids and sugars in the cell fluids increases the resistance to freezing.

Description: In attempting to interpret the results of two series of sheep feeding experiments, we have been confronted with the fact that the sum of the accepted figure for maintenance requirement and the allowance for the live weight increase produced does not account for the whole of the ration consumed. Sheep averaging 100 lb. live weight folded on swedes in the winter usually eat per week at least 100 lb. of swedes, 7 lb. of hay and 3½ lb. of cake and corn. Such a ration supplies per week about 11½ lb. of starch equivalent.Sheep fed in this way normally put on per week about 2 lb. of live weight increase, starting from store condition. It is true that figures for the composition of the live weight increase put on by store sheep are somewhat scanty, being practically confined to a series of analyses by Kern and Wattenberg (Journ. Landw. 1880) which give the composition of the live weight increase of store sheep as 44 per cent, water, 45 per cent. fat and 11 per cent, protein, which corresponds to 2200 calories or 2 lb. of starch equivalent per lb.The requirement for producing 2 lb. of such increase would therefore be 4 lb. of starch equivalent per week.Measurements of the maintenance requirement of sheep are likewise scanty. There are no recent measurements, but Armsby has recalculated the experiments of Henneberg, Kellner, Hagemann and Wolff, the most recent of which were made in 1893. These workers used two methods. The more scientific method of estimating by respiration experiments the storage of fat on a known ration and arriving at the maintenance requirement by deduction was used by Henneberg, Kellner and Hagemann. Recalculating and averaging their results, which differ widely, Armsby arrives at an average figure of 719 calories per day of net energy for the maintenance requirement of the 100 lb. sheep.

Description: The method used in this paper to reduce sunshine data is that developed by Fisher(1). It consists, briefly, in fitting to the distribution for each year, a curvewhere T0, T1T2, etc., are orthogonal polynomial functions of zero, first, second, etc., order in time. The constants s0, s1, s2, … etc., are found by least squares, and are correlated with similar rainfall constants (r0, r1, r2 etc.) and with the crop.The regression of the wheat yield on rainfall has already been found (1), so a method has been devised, whereby those results can be used in order to find the partial regression of wheat yield on the sunshine sequence, eliminating all rainfall effect.

Description: A résumé of the analytical methods hitherto employed for the chemical investigation of samples of silage has been given. It has been shown that these methods fail to yield trustworthy results when applied to the analysis of “sour” silage, owing to the disturbing effect of the presence of appreciable amounts of ammonium salts of organic acids in this type of silage.Investigations have been made into the behaviour of the ammonium salts of acetic, butyric and lactic acids, when solutions of these substances, in the presence and absence of the free organic acids, are (1) submitted to distillation in steam, (2) evaporated in the steam oven under conditions comparable with those obtaining during the determination of the dry matter of silage. The bearing of these results on the problem of silage analysis has been discussed.A modified analytical procedure for silage investigations has been devised which is capable of general application.

Description: 1. Previous investigations showed that certain Scottish soils were of glacial drift origin, that they were comparatively rich in unweathered silicates and therefore in reserves of plant-food, that they showed considerable variation in such silicates and were capable of classification accordingly. Some indication was also shown that the glacial drift, and hence the resulting soil, was sometimes of local origin, its character being determined by the underlying rock. In the present investigation a more extensive survey of Scottish soils has been made in order to discover to what extent these preliminary findings might be applicable generally.2. For this purpose soils have been collected from various localities in the north, north-east, west and south of Scotland, and have been analysed mechanically and the “fine sand” fraction examined mineralogically.

Description: Using the conception of the “ideal soil” a calculation has been made of the cohesion due to the capillary attraction between the particles when wetted. Experimental verification of this theory is afforded by cohesion tests on the ignited silt fraction separated from soil.

Description: 1. The exchangeable Fe, Al, Ca, Mg, K, Na have been determined in twenty soils from different parts of the East of Scotland, by extraction with N NH4Cl solution. Data on pH, “Lime Requirement” and loss on ignition are given for the sake of comparison.2. Only three soils were found to contain Fe and Al in exchangeable form.3. The content of exchangeable bases varies from 5·6 to 22·2 milligram-equivalents per 100 gm. air-dried soil.4. The evidence is insufficient to deduce any definite relationship between pH and “Lime Requirement” and the pH cannot be correlated with the content of exchangeable bases except in the case of soils similar in character.5. It is suggested that the differences in the relative proportions of the exchangeable bases indicate that there are on the one hand fundamental differences due to soil type and on the other hand fluctuating differences due to manurial treatment.6. Emphasis is laid on the fact that the degree of saturation of a soil is not necessarily indicated by the content of exchangeable bases. At present the absorptive capacities of the soils examined are not known.7. Until a sufficient number of soils have been examined and classified, it is unlikely that any satisfactory generalisation on the subject of exchangeable bases will be forthcoming.

Description: In the official methods of soil analysis followed in this country, the available phosphate is determined by Dyer's (1) method. This consists in determining the amount of phosphoric acid, which becomes soluble, when 200 gm. of soil are shaken continuously for 24 hours with 2 litres of water, containing 20 gm. of citric acid. The result is expressed as a percentage of the weight of soil. It is usual to infer lack of available phosphate if less than 0·01 per cent. P2O5 becomes soluble under these conditions. Hall (2) has suggested the necessity for a revision of this limit.

Description: An account has been given of an investigation into the changes which occur during the preservation of the oat and tare crop in the clamp silo.The material obtained from the clamp was divisible into three types: (1) An uppermost thick layer of mouldy material. (2) “Sweet” silage from the middle layers. (3) Wet “sour” silage from the bottom layer. The spoilt material in the top layer represented approximately 19 per cent. of the whole of the crop contained in the clamp, and in addition to this, the silage was extensively spoilt round the sides of the clamp to an average depth of 12 inches. In comparing the processes of ensilage in the tower and in the clamp, it should be remembered that spoiling of this type only affects the top few inches of the material in the tower silo.The loss of dry matter in the “sour” silage layer, arising from fermentation and drainage away of juice, amounted to more than one-fifth of the dry matter of the crop originally present in the layer. This represents a much bigger loss than any previously recorded at Cambridge in similar work with tower silos. An exceptionally heavy destruction of carbohydrates further characterised the production of the “sour” silage in the clamp.The loss of dry matter in the “sweet” silage layer was much smaller and was comparable in magnitude with that occurring during the production of “green fruity” silage in tower silos.The chemical characteristics of the “sour” silage samples were investigated and were found to conform with results discussed in a previous communication, namely, the samples contained a high proportion of volatile bases to amino acids, and the volatile acids were present in appreciable excess of the non-volatile organic acids.

Description: Much of the modern work on the physical properties of soil has been interpreted on a colloidal basis and more recently this hypothesis has been extended by the thermodynamical studies of Wilsdon and also by the investigations of two of us on an indirect measurement of the vapour pressure of capillary systems. There is evidence that the colloidal portion of the soil can be regarded as possessing a reticulate structure, possibly analogous to that shown by Zsigmondy to exist in silica gels. The pore space in soils is therefore an assemblage of voids and irregular capillaries ranging from ultramicroscopic dimensions in the colloidal portions to the macroscopic interstices between adjacent compound particles and the larger mineral fragments. Whereas in studies of evaporation and movement of water the total intersticial space is operative, the vapour pressure of soils at different moisture contents is very largely controlled by the minute pores associated with the colloidal portion and the larger voids have comparatively little influence. Vapour pressure measurements therefore afford a promising line of attack on the physical relations between the colloidal soil material and water, especially when the measurements are made on soils subjected to a variety of preliminary treatments, known to have a considerable effect on other physical properties. The effect of successive wetting and drying, heating and addition of salts are of especial interest in this connection.

Description: (1) There is a definite seasonal variation in the mineral content of the pastures examined between the months of May and October, which is most clearly shown by the CaO, which rises to a maximum and then steadily falls; and to a less extent by the silica-free ash, P2O5and Na2O.(2) The chlorine content did not show a corresponding variation; its tendency being to maintain its high percentage through the later part of the season.(3) The nitrogen, on the whole, showed a variation corresponding with the calcium, though the range was markedly less.

Description: (1) Bent-leg appears to be due to a mineral deficiency and can be prevented by a mineral supplement.(2) Bent-leg appears, by the growth curves, to be correlated with a general lower nutrition.(3) The occurrence of bent-leg on pasture grass would indicate theoretically that an extreme lack of some mineral constituent has become evident in the grass itself.(4) Pasture analyses show that these grave mineral deficiencies do actually occur in large pastoral areas, and that these areas are correlated with high stock death-rates.(5) The mineral elements of the ration are therefore no less important to the pastoral farmer than to any other stock feeder.

Description: 1. The reaction between lime sulphur and acid lead arsenate is shown to be small and to have little effect on the chemical properties of either material as a spray.2. It is shown that the oxidation of lime sulphur proceeds according to the empirical formula:CaS.Sx + 30 = CaS2O3 + Sx-1and that the calcium sulphides are hydrolysed in aqueous solution.3. The addition of lead arsenate has no effect on the amount of sulphur precipitated from the lime sulphur by oxidation or by the action of carbondioxide.4. Lead arsenate is only slightly decomposed by lime sulphur or by the oxidation products of lime sulphur, the main decomposition being due to the action of sulphuretted hydrogen formed by the hydrolysis of the calcium sulphides. This decomposition becomes marked in the presence of carbon dioxide which reacts on the calcium sulphide to form sulphuretted hydrogen.5. The fungicidal value of the mixed spray—as judged by the mildew killing properties of the polysulphides—is not less than that of lime sulphur alone. Additional fungicidal properties may be expected from the presence in the spray of soluble arsenates and thioarsenates.6. Judging by the chemical changes which take place in the mixed spray the insecticidal value of the lead arsenate would not appear to be greatly affected by the addition of lime sulphur.7. There is an increased amount of soluble arsenic formed by the action of carbon dioxide on the mixed spray which may prove sufficient in amount to cause spray injury.8. The A.O.A.C. method for the determination of sulphate sulphur in lime sulphur solutions is shown to be inaccurate. A method yielding more concordant results is proposed.

Description: In the foregoing communication on maize digestibility (i), reference has already been made to the early difficulties which arose as a consequence of attempting to make measurements on rations consisting wholly of maize and milk. During, the period in which a mixture of milk and flaked maize was being fed, the pigs developed constipation troubles, due, as subsequent results proved, to the almost complete digestion and assimilation of the ration by the animals. At the time, however, it was deemed expedient to alter somewhat the scheme of the experiment and to feed the maize along with a definite weight of coarse middlings. In this manner it was anticipated that the fibre of the coarse wheat offal would promote peristaltic activity in the intestinal tract and thus assist the passage of undigested food residues.The introduction of the middlings into the experimental ration made necessary the determination of the digestibility of this feeding stuff. The results of this trial are given for convenience in this separate communication.

Description: A hydrogen electrode apparatus for soils is described. Similar or adjacent soils may show considerable differences in pH value, with no changes in their degrees of buffer action, as shown in titration curves with lime water. In such cases the conventional “lime requirements” are correlated with the pH values, but no such relation holds in dissimilar soils. The pH value of a soil suspension is intimately connected with the nature and amount of the cations present. Neutral salts markedly increase the hydrogen ion concentration of both acid and slightly alkaline soils. Sodium salts, including the hydroxide, give lower hydrogenion concentrations than the corresponding potassium or calcium salts, and chlorides give lower pH values than sulphates. The degree of buffer action (slope of titration curve) is unaffected by the addition of a neutral salt. Previous extraction of a soil with water causes a considerable increase i n the pH value of its suspensions. A number of soils showed a regular increase of about 0·1 in pH. value for twofold dilution. The “salt effect” and “dilution” effect appear to be of the same type. It is recommended that the soil-water ratio of 1:5 be generally adopted. The indicator methyl red gives erroneous pH values in turbid soil suspensions owing to the absorption of the red form, which is apparently a cation capable of undergoing “base exchange” with the soil.

Description: Two fundamental explanations have been advanced to account for the unequal distribution of electrolytes on either side of a cell membrane: the one bases the unequal distribution on the existence of a cell membrane of so-called selective permeability, by which the membrane is endowed with the property of presenting varying resistance to the passage of different ions; the other regards the unequal distribution as being due to the selective action of the cell constituents themselves. This latter theory regards the cell primarily as a system in which the distribution of electrolytes is governed by the equilibrium existing on either side of a membrane permeable to electrolytes but impermeable to other ionised constituents of the cell.

Description: An investigation has been described in which an attempt has been made to measure the losses of dry matter in a number of regularly spaced layers of silage contained in a tower silo, the immediate object being to determine the average loss of nutrient matter in the entire mass of material. The work was continued over the period of two silage seasons. The more important findings are summarised below:1. It is usually asserted by writers on ensilage that the attainment of such high temperatures as are necessary for the production of “sweet” silage necessarily involves an excessive loss of the dry matter of the crop as a consequence of the oxidation of carbohydrate. This statement has been shown to be erroneous both on theoretical grounds and on the grounds of actual measurements of the losses of dry matter entailed in the production of “sweet” silage. The amount of destruction of carbohydrate bears no significant relation to the temperature attained during preservation, and the factors of (a) juice drainage, (b) bacterial decomposition of carbohydrate, (c) partial spoiling by undesirable bacterial activity, as with “sour” silage, are of much greater significance in causing unduly large losses of carbohydrate.2. The results obtained in this investigation with crops containing from 26·5 to 33·9 per cent. of dry matter show that “acid brown” silage can be made in the tower silo with an average loss of dry matter equal to 5–6 per cent. of that contained in the green crop. It is further concluded that “sweet” silage, if made under good conditions, can also be produced in the tower silo with an average dry matter loss of the same order. With “green fruity” silage, the average loss under proper conditions of ensilage in tower silos is of the order of 8–9 per cent. The evidence affords strong disproof of the statement that the ensilage of green crops cannot be accomplished without large losses of nutrient matter.

Description: Six heifers have been measured every week, for 5 weeks before calving and 6 weeks after calving, with the object of ascertaining what errors would be introduced by taking one set of measurements during such a period, as representing the size of the heifer at parturition.The gross standard error was found to be 0·834 cm. in measuring shoulder height and back length and 0·605 cm. in measuring height to the elbow.During the period these heifers were growing as follows: shoulder height, 0·159 cm. per week; back length, 0·124 cm. per week; and elbow height, 0·079 cm. per week.When allowance was made for growth the net personal errors of measurement gave standard errors of 0·636 cm., 0·727 cm., 0·547 cm. respectively for shoulder height, back length and elbow height, and the errors were, apparently, distributed normally.

Description: (1) A review of the literature on the digestibility of wheat by poultry revealed the fact that, whereas there appeared to be but little variation in the digestibility coefficients for organic matter and N-free extract, considerable variation existed in the digestibility coefficients for crude protein, fibre and ether extract. It was considered desirable, therefore, to carry out digestibility determinations of known varieties of English wheats in order to ascertain how far such variations could be attributed to different varieties of wheat having been used in these experiments.(2) Experiments carried out with Little Joss wheat and Yeoman II wheat gave closely concordant results for all nutrients other than ether extract.(3) The results obtained in these experiments support the view that the digestibility of crude fibre by poultry is negligible.(4) Except in the case of crude fibre and ether extract, poultry appear to be able to digest wheat as efficiently as other farm animals. Poultry are, however, distinctly inferior to other farm animals in their capacity to digest crude fibre and ether extract.(5) The results of the present experiment show general agreement with previous work, except in the case of protein, where the digestibility coefficients are distinctly higher than those hitherto recorded. The explanation of this result may possibly be sought for in the improved methods used in the estimation of uric acid and ammonia

Description: The following solutions were tested with respect to their fungicidal properties towards the “powdery,” conidial stage of Sphaerotheca Humuli on young hop-leaves in the greenhouse.(1) A solution of potassium polysulphide containing 0·092 per cent. polysulphide sulphur proved fungicidal, whilst one containing 0·066 per cent. was not quite fungicidal.(2) A solution of sodium polysulphide containing 0·12 per cent. polysulphide sulphur proved fungicidal. It seems probable that solutions of sodium and potassium polysulphides possess the same fungicidal values.(3) Lead arsenate proved to be considerably less fungicidal in action than lead thioarsenate, dicalcium arsenate or disodium arsenate. A solution of lead arsenate containing 0·1 per cent. As2O5 proved to be not quite fungicidal, while one containing 0·204 per cent. As2O5 proved fungicidal.(5) Solutions of calcium polysulphide and of lead arsenate at concentrations below fungicidal strength when mixed together proved to be fungicidal.

Description: The exploitation of the herbage by means of the herbivora is a most ancient process. It seems at first sight that special nutritional problems are not involved, since flocks and herds are kept under conditions approximating very closely to the original environment of their species. In comparatively recent years, however, masses of herbivora have been in some cases either confined so that their range is greatly limited from that of their widely-grazing forbears, or transferred bodily to grasslands previously uninhabited by them, or transformed by the skill of breeders into creatures with a much higher output, and in consequence, a much higher intake. These novel factors have produced problems of their own which are not yet solved, though they have been, with some success, tackled by the practical man largely by empirical methods.

Description: 1. Experiments in which were measured the resistances to (a) transverse breaking, (b) crushing, and (c) parting under tensile pull of standard blocks of soil prepared in different ways and under particular moisture conditions are described and discussed.2. The soils examined comprised three highly colloidal siliceous soils containing amounts of calcium carbonate ranging from 7·2 to 0·2 percent., and two red lateritic soils.3. The most significant results were obtained by employing, in a special tenacity apparatus, granular test-blocks, prepared by moistening sieve-graded dry soil packed into rectangular moulds. The results thus obtained are believed to furnish a reliable measure of the cohesiveness of soil colloidal matter, especially in soil blocks that have previously been brought to constant moisture content in a humidifier. The method of preparation simulates the effect of rain in causing the “running together” of colloidal soil particles.4. The relative cohesiveness of the soils examined appears to follow the same order as their rates of settling from aqueous suspension. This observation strengthens the view that cohesiveness in colloidal soils is to a certain extent due to chemical forces that depend on the presence of active atoms or atomic groups possessing powerful fields of residual affinity, although probably film tension also plays a part.

Description: In determining the nitrogen content of the heavy black cotton soil of the Central Provinces, India, by the Kjeldahl process it is important that the determinations be carried out on moist and not on air-dried soil. These soils apparently contain a cementing material probably containing iron which is insoluble in concentrated sulphuric acid and protects organic matter in the interior of the compound particles from the action of the acid.It may be that these soils are peculiar in this respect, but it would seem of importance that other workers should take into account the possibility of error in the estimation of nitrogen when using air-dry soils.In conclusion it is with great pleasure that I acknowledge my indebtedness to Mr F. J. Plymen and Dr H. E. Annett for their valuable suggestions and advice during the course of this work.

Description: (1) The cotton growing area in the Gezira consists of a heavy clay soil, the proportion of clay being about 50–60 per cent. in the upper layers with a maximum at about the 4th foot.(2) The water soluble salts amount to about 0·2 per cent. The proportion is highest at about the 3rd to 5th foot. The alkalinity (pH) is highest at the 2nd foot.(3) In the first 2 feet, the salts consist mainly of sodium carbonate and the third and fourth of sodium sulphate.(4) The irrigation (Blue Nile) water is of excellent quality as judged by its natural chemical composition. The concentrated water, however, contains a very high proportion of alkali salts. It is estimated that a season of normal irrigation would cause an increase of 0·01 per cent. in the alkali content of the first 4 feet of soil.(5) The sodium salts can readily act on the clay and the sodium clay so formed hydrolyses with the formation of sodium carbonate.(6) Samples taken at the same time from good and bad plots in the same area show a strong correlation between salt content and cropyielding power. There is also a correlation between pH and fertility.(7) In the same season and in the same area, virgin (i.e. unirrigated) plots give a higher yield than those which have been previously under the same system of cultivation.

Description: Maps of soil resistance to ploughing have been drawn up from the dynamometer readings over several seasons for the Rothamsted classical plots, carrying wheat, barley and roots respectively.The conclusions as to the effect of manurial treatment are only of a general nature at the present stage of the work. Such differences are certainly small in comparison with the natural variations in the soil.In the case of the Broadbalk wheat plots the drawbar pull values have been shown to have a close relationship with the clay content of the soil and with certain aspects of the soil drainage.

Description: 1. A number of soils—treated with acid and washed free from it—have been found to possess in high degree the power of destroying phenol. Soils derived from certain geological formations seem to possess this property more than those derived from others.2. This effect has been obtained from soils treated with sulphuric, hydrochloric, nitric, phosphoric, formic, and acetic acids.3. The bulk of the loss of phenol is instantaneous; but the maximum loss is attained within about 20 hours.4. An inverse relation seems to exist between the period of contact of acid with soil and the extent of the subsequent loss of phenol.5. The loss of phenol is prevente d by several treatments—ignition of soil before or after acid-treatment; treatment with alkalis or sulphurous acid after acid-treatment; autoclaving the soil after acid-treatment and also in less degree before acid-treatment.

Description: An account is given of a reliable technique that has been evolved for making dynamometer measurements in the field. It has been shown that quite small variations in the trace of the drawbar pull are significant, and correspond to actual variations in the resistance of the soil. No significant change in drawbar pull is produced by imperfect adjustments in the hitch or set of the implement within the limits met with in ordinary ploughing, except in so far as the depth of working is affected. The drawbar pull bears a linear relationship to ploughing depth within the region of ordinary ploughing. The slope of the land is without appreciable effect on the drawbar pull up to gradients of 1 in 40.

Description: An account has been given of a digestion trial with sheep which was designed to assess the nutritive value of “sweet” rye grass and clover stack silage. The most noteworthy feature of the results was the appreciable depression of digestibility suffered by the crude protein of the crop as a result of ensilage. A tentative explanation of this effect has been put forward, based on a consideration of the high temperature attained in the stack.In conclusion, the writer would like to state that the silage was made under the direction of his colleague, Arthur Amos, Esq., M.A., and to him thanks are due for permission to use the fodder for the purposes of the feeding trial. The writer also tenders his thanks to Mr G. Thurlbourn for considerable assistance in connection with the analytical work and the care of the animals.

Description: Part I. The changes in amount and composition of the mammary secretions of a heifer in its first pregnancy are recorded.The most striking feature is the abrupt appearance at half-way through pregnancy of a viscous secretion consisting largely of globulin.These results are extended to the primiparous and to the multiparous “dry” goat.Colostrum is shown to be normal milk admixed with the globulin secretion.The significance of the globulin is discussed. Reasons are advanced indicating that it may be an excretion of the cell when it changes from the growth phase to the secretory phase of life.The stimulus to mammary growth is briefly discussed.A partial analysis is given of the secretion from the tubercular udder of a cow. This secretion resembles somewhat the secretions of mid-pregnancy.Part II. Instances are given of cases of premature lactation in the goat, and analyses are recorded of these secretions.These cases are discussed in the light of Part I of this paper, and their bearing on the corpus luteum theory of mammary development is considered. The sexual precocity of the goat is such that the mammary growth may in all cases have been due to luteal influences.A few cases of premature lactation in the cow are also reported.The theory that the foetus produces a hormone inhibiting lactation is shown to be unnecessary.

Description: (1) Removal of chlorine ions by soil from dilute hydrochloric acid solution has been shown to take place under the experimental conditions employed.(2) Interaction between dilute acids and soil (free from carbonates) has been studied. The results show that hydrochloric acid, nitric acid, sulphuric acid, acetic acid, citric acid and phosphoric acid all react with soil. The state of equilibrium between the soil and the acid solution can be satisfactorily expressed by Freundlich's equation. The order of reactivity of the soil towards various acids does not follow any obvious rule.(3) The various soil fractions do not show any fundamental difference in their equilibrium relationship with regard to an acid solution; the order of their power to react with acid following inversely the order of the size of particles in them.(4) The experiments recorded seem to support the view that the interaction between soil and acids is a surface phenomenon.

Description: 1. Of 583 pig foetuses of all ages, 331 were found to be males and 252 females, giving a male percentage of 56·8, which is much higher than the approximate equality between the sexes that seems to exist at birth. This result confirms Jewell, who found a male percentage of 55 among 1000 cow foetuses.2. These 583 pig foetuses when classified by weight (0–100 gm., 101–300 gm., 301+gm.) gave the following percentages of males for the respective groups, 59·1, 57·0, 53·2. In other words, the percentage of males decreases as gestation proceeds, a result which can only be brought about by a differential mortality of males and females. It would appear that the percentage at conception must be very near 60 per cent. or 150 males per 100 females.3. The sex-ratios of foetuses from the left and right cornua show no significant difference, 55·0 for the right and 54·7 for the left.4. The males were found to average about 7 per cent. heavier than the females.5. There seems to be an inverse correlation between the number of foetuses in a horn and their average weight. Foetuses from the left cornu have a slightly greater weight than those from the right, and this may be connected with the slightly inferior fertility of this horn.6. The excess of males at conception is discussed in the light of the implications of the chromosome mechanism of sex determination, and reference is made to the greater mortality of the males.

Description: A Unique correlation has recently been obtained from some experimental data at Rothamsted. In the autumn of 1924 a set of 47 unmanured plots were laid out in Sawyer's Field, and were sown with wheat to test the uniformity of the fertility of the soil. The plots were each ·098 acre. The produce of grain and straw from each was recorded, and an examination of the figures showed that the straw yield recorded for plot 1 A was much lower than one would have expected under normal circumstances. A careful enquiry into the matter revealed that by an oversight a weighing of straw had been removed from the scales before the weight had been entered in the record. As it was impossible to verify the exact value of the missing entry, the yields from this plot were omitted from all statistical reductions of the data, leaving 46 plots upon which to base an estimate of the various statistics.The soil was found to be very variable in fertility, the average yield of total grain per plot being 149·57 lb., with a standard error of 6·39 lb. and the average yield of total straw per plot was 194·35 lb., with a standard error of 7·55 lb.The grain and straw yields of the 46 plots are shown in the accompanying diagram. The very close association between the total weight of grain and total weight of straw is evident. The amount of the relationship was measured by correlating the 46 pairs of values.

Description: (1) The relationship between phosphate soluble in 2 per cent, citric acid and total phosphate present has been investigated in the following cases:(a) Phosphates of known composition.(b) Basic Slags.(c) Mineral Phosphates.(2) The relationship is best shown graphically and in nearly all the above cases is a straight line passing through the origin.For each of three basic slags of widely differing citric solubility, the graphis a straight line showing that citric solubility is a definite constant, independent of the weight taken in the test, when allowance is made for a small constant error in the determination.(3) The ratio soluble phosphate/total phosphate in the case of the mineral phosphates Gafsa, Ephos, Nauru, and a West Indian phosphate, depends on the weight taken in the test, the graphs are not straight lines.

Description: (1) Hydrogen peroxide oxidises or renders soluble a portion of the organic matter of soils. It appears to be without action on fibrous organic substances such as cellulose and lignins. Humified material seems to be oxidised completely or brought into a water soluble state.(2) Treatment with hydrogen peroxide is proposed as the basis of a method for estimating the approximate degree of humification of soil organic matter.(3) Among the soils examined, the highest degree of humification is found in peats and uncultivated soils. It is possible that the degree of humification is correlated with the prevalence of anaerobic conditions.

Description: (1) Rather over 50 per cent, of the cows in this country probably possess accessory or supernumerary teats, the number of which varies from one to three.(2) In many cases at any rate, these teats are associated with additional glands.(3) These additional glands are frequently functional and secrete milk.(4) Ordinarily this milk is absorbed into the circulation, the lactose being secreted in the urine.(5) The presence of active accessory or supernumerary glands is an undesirable characteristic since it involves the formation of milk which is not utilised.

Description: During the investigation in connection with maize digestibility recorded in the current issue of this journal (1), a period of feeding was carried out in which the two pigs received a ration consisting of unsoaked crushed maize and whole milk. Although it was found necessary to discontinue the main maize trial along these lines, the results of this isolated period are not without interest, since they enable conclusions to be drawn concerning the extent of the digestion and assimilation of the constituents of milk when fed to swine.The crushed maize used in this period was from the same stock as that fed in the mixed maize and middlings periods. The daily ration consisted of 2000 gm. crushed maize together with one quart of whole milk; it was given in two equal portions during the day, the milk and a little water being mixed with the dry maize in the trough at the time of feeding. The presence of the milk appeared to make the ration attractive to the animals, since ready and complete consumption was obtained.

Description: The removal of soluble humus by alkaline extraction from both a garden and a field soil reduced the productiveness over a series of crops in pot experiments. The field soil showed an initial but temporary increase in productiveness.

Description: 1. The main results of soil investigations on the rôle of aluminium in soil infertility are reviewed, with particular regard to the physicochemical principles involved.2. Magistad's conclusion that soils or other nutrient media whose reaction values lie within the range pH 4·7 and pH 8·5 do not contain aluminium in soluble form, and are probably therefore not toxic to plants, is discussed in the light of modern knowledge of the properties of hydrous alumina and its peptisation phenomena.3. Dialysis experiments which have led to this generalisation are criticised on the grounds that they do not take into account the disturbing effect of dialysis on hydrous colloidal systems, and that dialyser membranes do not simulate plant-cell membranes.4. Aluminium may possibly penetrate plant-root cells, and, under certain conditions, may be translocated, within the plant body, in at least four different forms, namely, (a) simple ions, (b) more complex colloidal electrolytes, (c) co-ordinated complex anions, and (d) organo-compounds. These may conceivably be interconvertible.5. Aluminium appears to exert true toxic effect only when presented to plant roots as simple ions, or as the more soluble colloidal electrolytes. Apparently, the degree of toxicity varies for different plant species.6. The reaction conditions of nutrient media and of plant saps doubtless largely decide the form in which aluminium occurs therein. At reactions approaching the isoelectric point of hydrous alumina, toxic effects may never be exerted, although the assignation of a strict reaction-range applicable to all soils or nutrient media, and to all plant species, is probably inadmissible.7. Non-toxic forms of aluminium may apparently accumulate under certain conditions at definite tissue regions of certain plants, and may disturb their metabolic processes, disposing the plants to certain diseases.8. Within the reaction-range at which toxic aluminous solutes cannot exist in soils or other culture media, hydrogen-ions may exert controlling influence on plant growth, and may thus be of major significance in natural plant distribution, and in the behaviour of plants growing in normal agricultural soils.

Description: Attention is drawn to the fact that there is variation, both morphological and physiological, within the aggregate of plants known as “white clover.” After a detailed study of some of the characters of the plant, it has been determined which of these are constant and which are alterable by external conditions.The cyanogenetic behaviour has not been found correlated with any recognizable external feature of the plant, and has been found constant from year to year, and under different soil conditions. For this purpose, separate plants grown in pots and “clone” plants on various soils were used.As a result of the study of distribution of cyanogenetic and acyanogenetic forms of white clover, it has been found that “positive” or “negative” plants give rise, under “open” conditions of pollination, to offspring approximately 75 per cent, of which are possessed of like cyanogenetic character.

Description: 1. The omission of the tension in the air-water interface has introduced an erroneous factor into Haines’ formulae; certain additional factors have also crept into his expressions for average stress.2. With these corrections, the stress due to moisture varies comparatively little with changing water content, though falling slightly throughout the range. The energy needed to cause rupture rises continuously in a manner not unlike Haines’ measurements, and should more probably be associated with them than should the tensile stress.3. The geometrical approximation used by Haines gives a close geometrical representation of the figure, but a mechanical approximation which is less satisfactory. Since neither the formulae connected with the true curve, nor the tables needed to use them, are readily, accessible, sufficiently exact numerical data have been here put on record.

Description: It is of great importance that milk should possess a pleasant flavour, but in spite of much trouble which is devoted by farmers and dairymen to this aspect of dairying, it happens from time to time that mishaps do occur. Taints and flavours in milk are due chiefly to the following three causes:1. The activity of contaminating micro-organisms.2. The action of milk on metals.3. The influence of the foods eaten on the milk produced.It must be admitted that we have very little knowledge of the subject of milk flavours and taints, and there seems little doubt but that the blame for many taints caused by micro-organisms has been associated wrongly with foods and sometimes with manures.

Description: Data from 26 flocks, involving a total of 5014 pure-bred Southdown ewes, were available for analysis and discussion. For ewes of all ages the proportion giving birth to twins is closely associated with the total yield of lambs, and while barrenness and abortion may to a certain extent be due to the same causes, it is those factors which cause abortion which also affect the yield by reducing the number of single births, rather than the number of multiple births.The low fertility of shearling ewes is due to barrenness through reduced or delayed ovulation.The writer wishes to express his thanks to the breeders who supplied the records of their flocks and particularly to the Honorary Secretary of the Southdown Sheep Society for his help in the collection of these records.

Description: Attention has been drawn to our ignorance concerning the nature of the proteins of green forage plants and the gap in the science of nutrition which arises thereby in trying to apply to forage plants results obtained from proteins of concentrated foods.Methods of extraction of proteins from green tissue are outlined and applied to the study of the proteins of some common representative leguminous plants.The proteins so isolated have been analysed and characterised. Proteins thus prepared were found to resemble each other closely with respect to distribution of nitrogen into three groups.Representative samples of proteins were found to differ appreciably in their content of the different diamino acids as determined by the van Slyke method, showing variation to occur in the composition of protoplasmic proteins within a natural order, which confirms the observations of other workers on seed proteins within a natural order.The occurrence of large amounts of mineral matter in the extracts from lucerne, vetch and sainfoin, but not in those of the two clovers, together with the difficulty of obtaining pure samples of proteins from the clovers, points to the slightly less nutritive properties of the latter owing to the lesser availabilities in them of both the protein and ash.The nitrogen distribution in the protein-free extracts shows the amide nitrogen to be constant but ammonia nitrogen to be variable.

Description: 1. A measure of the errors involved in the weighing of dairy cows for experimental work is presented.2. Methods of avoiding a considerable part of these errors are suggested.

Description: An account has been given of an investigation which was designed to test the efficacy of the process of ensilage in the stack for preserving hay crops which are in danger of spoiling in consequence of adverse weather conditions.The character of the ensiled crops and the weather conditions at the time of ensiling, together with the process of building the stack, have been described in detail.The results of continuous temperature readings in the stack have been given in graphical form. The significance of the two distinct temperature maxima which characterized the temperature curve has been discussed, and the importance of this method of investigation in regard to the elucidation of the processes which go on during ensilage has been emphasized.The chemical character of the “sweet” silage samples obtained from experimental bags buried in different parts of the stack has been investigated. The losses of dry matter resulting from fermentation and drainage have been determined and the changes affecting the individual constituents of the crop have been followed quantitatively. The results so obtained have been compared with similar figures referring to the process of ensilage in the tower and the clamp.It has been shown that the loss of dry matter in the “sweet” silage layers of the stack compares satisfactorily in magnitude with the losses accompanying the preservation of crops in the tower silo and is appreciably smaller than that associated with the production of “sour” silage in the clamp.

Description: 1. Healthy tubers and “primarily infected” tubers, at time of lifting, appear to be similar both in external appearance and chemical composition.2. On drying at laboratory temperature (about 60° F.) healthy tubers lose weight much more quickly than “primarily infected” tubers. In addition, the latter remain in a “hard” condition which persists even after sprouting whereas the former become soft and flabby.3. It is suggested that healthy “seed” may be separated from “primarily infected” seed on this basis.

Description: Analytical data are recorded which indicate that the application of artificial fertilisers to grass land may result in considerable modifications in the mineral content of the herbage of these pastures. The constituents which appear to show the biggest variations are calcium and potassium and, to a lesser extent, phosphorus. Coupled with any marked increase in the calcium content of the herbage, there is generally to be found an increase in the percentage of nitrogen.

Description: At the Bournemouth meeting of the British Association in 1919, Dr. J. W. Evans, in his characteristically stimulating address to Section C, pleaded for the closer examination of sediments by geologists in the field. He instanced especially the presence of rhythmic banding on a small scale in sediments of widely varying ages as a phenomenon badly in need of further study. Engaged in field work on the oil-bearing Tertiary rocks of Burma, the writer has been struck by the repeated occurrence of rhythmic banding in those beds. The present note embodies the firstfruits of the detailed examination of the banding.