1. Series of yields (root weight) of twenty-five plots of Barnfield mangold field are analysed into components representing (a) deterioration, (b) slow changes other than steady deterioration, (c) annual fluctuations. The two first of these components are exhibited graphically from 1876 to 1930.

2. Yields are well maintained on the dunged strip, except for the last few years. This falling off does not appear in the other strips, and may be due to a falling off in the quality of the farmyard manure in the last five years.

3. On the strip receiving farmyard manure and on that receiving superphosphate the plots receiving nitrate of soda yielded more highly than any others; on the strips receiving complete minerals, and on that receiving superphosphate and potash, the two plots receiving rape cake in one case, and sulphate of ammonia and rape cake in the other, gave higher yields than nitrate of soda; on the strip receiving no minerals the result is intermediate, there being little to choose between these three plots. On all strips sulphate of ammonia is the least satisfactory of the four nitrogenous dressings tested.

The variable viscosity which is shown by colloids generally as the rate at which they are sheared is varied leads to more striking anomalies in the behaviour of concentrated suspensions such as clay pastes when they are subjected to forces tending to make them flow. Bingham and Durham (l) first showed that when clay pastes were forced through capillary tubes, not only did the amount of clay squeezed out per second increase more slowly than the pressure applied, indicating a diminishing coefficient of viscosity, but also that there was evidence of a limiting shear, due to the consistency or cohesion of the particles, below which no flow would take place. It is the existence of this latter criterion that distinguishes clay from a weak suspension, e.g. of sand grains in water. This combined effect of cohesion and viscosity Bingham calls plasticity, and modifies Newton's law of viscous flow by the addition of a constant to allow for the cohesive force. Nevertheless, owing to the fact that the coefficient of viscosity is a function of the velocity gradient instead of being constant as in a homogeneous liquid, and that this velocity gradient is not known in the capillary tube viscometer, results as between one viscometer and another, or between two flow tubes of different size cannot be reduced to a common basis for comparison except by empirical trial. Keen and Scott Blair(2), Scott Blair and Crowther(3), and Schofield and Scott Blair(4) have repeated Bingham's experiments in an improved apparatus of the flow tube type, which they call a “plastometer.”

Nutritive values can be resolved into two factors-quantity and quality. The former is represented by the gross energy and the latter by the coefficient of availability (D/T – 0·35), where T is total and D digestible organic matter.

In the natural, vegetable feeding stuffs the gross energy of the total organic matter is practically the same in all cases except those which are peculiarly rich in oil and protein (cakes, etc.). The coefficient may therefore be applied directly to the total organic matter and, subject to a correction in the case of cakes, nutritive values may be expressed in terms of available organic matter (D–0·35T). These terms may be translated into energy values or starch equivalents by simple multiplication.

The method is simple and illuminating. It shows that the nutritive value of the total organic matter depends almost entirely upon its digestibility and, except in the case of cakes, only to a negligible extent upon its chemical composition. Nutritive value is not proportional to digestibility but a linear function of the same, and in substances of low digestibility, slight change in digestibility may cause manifold alteration in nutritive value.

The results discussed in this paper are based on the weights and composition of the excrements of eight pullets, fed for the periods stated on three rations, which differed only in the amounts of calcium and phosphorus supplied in various combinations. The total amounts of calcium and phosphorus supplied daily were approximately the same in all cases.

The birds were 5 months old White Wyandottes, and increased considerably in weight during the experimental period. No eggs were laid, but Pullet No. 2 died of prolapsus of the oviduct, and was found to have seven nearly full-sized yolks and one unshelled egg in the oviduct.

Copper has been detected in a large number of plants, and is probably present in very minute amounts in all vegetation. Estimations of copper content of a number of plants have been made, notably by Fleurent and Levi(1), Maquenne and Demoussy(2) and McHargue(3).

1. The typical profile of south-western Nigeria formed over acid igneous rocks under alternating conditions of percolation and evaporation is described. The profile being (a) brown sandy soil, (b) concretion layer, (c) red clay, (d) mottled red and white clay, (e) whitish clay, (f) rotting rock. Acidity increases with depth.

2. Analyses of the concretion layer show that it consists chiefly of silica (quartz), ferric oxide, and occasionally some manganese. Alumina does not occur to a large extent.

3. From studies of the mobility of the iron and soluble salts throughout the profile it is suggested that the profile is developed by a rise of an iron sol which is deposited on a layer of quartz to form the concretions.

4. The Yoruba name “Il***pa” has been adopted by the authors for describing such a profile.

1. Barley plants, carefully sampled, were harvested weekly during the season. Growth measurements were made and various analyses carried out on the dried material.

2. Both ash and protein showed an initial increase followed by a steady fall as development proceeded.

3. The Cross and Bevan cellulose fraction, which may be taken as the natural cellulosic fabric of the plant, increased from 30 to 53 per cent., showing an initial peak, and later a stationary period.

4. The amount of cellulosan (or associated polysaccharide) in the cellulose increased with development, and markedly so after the point at which growth increments lessened.1

5. Lignin increased steadily until the last week or so, the fall then probably being due to the increased weight of the grain with respect to the straw.

1. The fungicidal action of vegetable oils on the conidial stage of the hop powdery mildew, Sphaerotheca Humuli (DC), Burr., is a property common to glyceride oils. When applied with 0·25 per cent. Agral I, the various samples of vegetable and animal oils examined, with the exception of castor oil, proved fungicidal at a concentration of 0·5–1·0 per cent.

2. The fungicidal action of glyceride oils is associated with the glyceride structure and, in the presence of Agral I, is unaffected by the presence of those impurities of the oil which are removed by refinement.

3. Glycerol, at 4 per cent., is not completely fungicidal and, under the conditions of the experiments, causes leaf injury; oleic acid, at 1 per cent. is phytocidal; triolein, prepared by synthesis from glycerol and oleic acid, is fungicidal at 0·5 per cent. and causes no injury to the leaves.

4. The fungicidal properties of glyceride oils are affected by the type of emulsification used and the stable emulsions produced by the twosolution oleic acid method are less effective than the unstable emulsions obtained by agitation with dilute Agral I solutions.

By the use of a solution of p–nitrophenol in lime water a rapid and simple measurement can be made of the lime taken up by a soil sample in reaching neutrality. The same method applied to acid-washed samples gives the exchangeable base content at pH 7.

The reduction in the electrical conductivity of a mixed solution of K2HPO4 and KH2PO4 caused by the addition of soil is a measure of the potassium uptake, and is therefore an indication of the “;base exchange capacity” of the soil at pH. 7. Two disturbing factors are noted, and it is concluded that the method is likely to be most useful where a rapid comparison of soils of a similar nature and pH is required.

The conclusions that have been arrived at from the foregoing statistical examination of the available data on the physical properties of the Natal soils used by Coutts are:

(1) The base exchange capacity of the soil, as measured by Schofield's potassium phosphate buffer method, appears to be of predominant importance for predicting several of the soil properties, as for example the sticky point and the moisture content at 50 per cent. relative humidity. On the other hand, the clay content seems to be of quite minor importance in predicting these soil properties.

(2) The information from the data supplied by the Keen-Raczkowski box indicates that ω, the weight of water held per gram of soil in the box is very closely correlated with the base exchange capacity of the soil, while the swelling and pore-space parameters are more complex. The swelling υ seems to be dependent on the base exchange capacity of the soil and a term probably representing the structure of the soil, while the pore space p seems to be dependent on the clay content and a soil structure term. By choosing an appropriate definition of the pore space practically all the structure information given by the swelling parameters is contained in it.

Abnormal leg trouble or perosis occurred in chickens getting an excessive amount of meat and bone meal in their ration, and rarely occurred when the bone meal content was low or nil.

The use of the battery brooder was found to intensify bone deformities, when the ration was unsatisfactory in mineral balance.

The floor space allowed was not found to be a factor in perosis.

Under the conditions of the experiment, slipped tendons were not produced by feeding calcium carbonate (ground limestone) in the ration.

The protein content of the ration and the rate of growth did not materially affect the occurrence of perosis.