The theory of the capillary behaviour of moist soil has been further amplified for the ideal case and its relationship to various soil properties considered. Over part of the moisture range which has been dealt with by other authors it is found that there are alternative forms for the water distribution. This appears to explain why some differences of opinion have been expressed regarding some of the main points presented in a previous paper.

The theory is considered in relation to capillary rise in soils as well as to the problem of cohesion previously dealt with. It is shown that the moisture distribution attained by capillary rise can be inferred from simple direct measurement of the suction pressure. Various other experimental illustrations of the theoretical conclusions are introduced.

All Cows. It is proposed, in dealing with this question, to follow the same lines as in the previous Part—namely, to describe the effect as found from all the Norfolk records (comparing the results, where possible, with those found in the case of Penrith) and then to treat the various breeds, and high and low yielders separately, in order to bring out any peculiarities that may exist as regards those groups.

It has already been seen that, as would be expected, the length of the S.P. very largely influences the length of the lactation, and it would seem probable on the face of it, that as pregnancy progresses the milk flow declines; this latter is dealt with in Section B of this Part, but we are here concerned with the total effect of both of these on the yield of milk in the lactation.

A lighting (paraffin) oil bought casually, such as is often used in paraffin emulsions for spraying, has been subjected to fractional distillation, and shown to be unsuitable as a spraying oil.

Approximate solubilities at room temperature of various “oils” in solvents such as soap solutions with and without the addition of phenols, hydrogenated phenols and pyridine, have been determined. Spray fluids containing paraffin oil, benzene, and aniline in solution are economically possible, but coal tar fractions such as anthracene and creosote oils, will, owing to lack of solubility, have to be applied to plants as emulsions. Cresylic acid is the best aid to solution of paraffin oil, but is probably more injurious to foliage than the dearer, hydrogenated phenol, hexalin.

Experiments have been made on the influence of temperature when using soap (sodium oleate) and gelatine as emulsifiers; rise in temperature is found to facilitate the formation of emulsions in soap solutions, but to have a much more complex effect when gelatine is the emulsifier. A possible explanation of these facts is given.

During recent years a large number of samples of milk having a peculiar flavour have been sent to this Institute by farmers, retailers, and wholesalers of milk.

The flavour is marked and has almost invariably been described as “oily.” In many instances it has been referred to as the “castor oil flavour.”

Although, as would be expected, the opinions of individuals on the flavour of such samples were not unanimous the majority agreed that “oily” was an appropriate name and since this is the name by which this taint is known to the trade it is proposed to retain it.

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

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

1. As a result of soaking in water at body temperature (38° C), foods show variations in swelling ranging from approximately 10 per cent. to 260 per cent.

2. The volumes of equal weights of different foods after soaking also vary within wide limits. The percentages of moisture in the soaked foods show corresponding variations, being in some cases as high as those found in roots or green fodder.

3. These facts have led the authors to put forward a new conception of “bulk” in assessing the value of a ration.

4. Feeding experiments have been carried out to determine how far this factor of bulk is applicable in practice.

5. In the case of pigs of 40 to 80 lb. live weight, the bulk occupied by the foods did affect the quantity of food taken.

6. With calves, the swelling capacity of the concentrated food did not yield any definite results so far as food consumption was concerned.

1. Percentages of fat, solids not fat and protein were determined in over 700 samples of mixed milk from 15 herds during 1925–26. In the case of fat content, nine herds produced one or more samples below 3 per cent., one herd recording 25 per cent, of samples below this limit. With regard to solids not fat, twelve herds produced milk containing less than 8·5 per cent, on one or more occasions, the highest percentage of deficient samples recorded being 40.

2. Frequency distributions of fat, solids not fat and protein percentages in the samples analysed, are given, together with standard deviations, and mean percentages with probable errors for these three constituents.

3. Correlation tables of fat with solids not fat, and protein with solids not fat have been prepared, and graphs illustrating the variations are given.

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

(1) The formation of laterite and lateritic soils in Sierra Leone has been studied and the mode of formation and the composition of these soils is described.

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

In a former communication (1) a study has been made of the influence of the stage of lactation on the yield and quality of the milk, and in the following paper a similar investigation has been made of the influence of the age of the cow on the same factors.

Mackintosh (2) finds a gradual increase in yield up to the 4th or 5th lactation period, and a decrease after the 7th or 8th; thus a heifer calving at 2¾ to 3 years gives 60–70 per cent. of the amount it will produce as a mature cow; after the second calf it gives 80 per cent. and after the third 90 per cent. Tocher's results (3) show an increase from 85 per cent, of the maximum yield at 3 years to a maximum at 7½ years, and a subsequent fall to 90 per cent. at 12 years of age.

The practice of applying nitrogenous fertilisers to cereal crops as a top dressing is one which has become firmly incorporated into normal farm routine.

The classic wheat experiment on Broadbalk field shows that to apply all the nitrogenous fertiliser at the time of drilling the seed in autumn leads to a diminution in crop when compared with the yield of a plot in which only a quarter of the nitrogenous fertiliser was applied in autumn.

1. 670 samples of the mixed milk from 15 herds were analysed, and the average percentages of total ash, soluble ash, insoluble ash, lime and phosphoric acid are given.

2. Tables showing frequency distributions are also given, with the standard deviation, mean and probable error of mean for each constituent determined.

3. Various correlations of these constituents with solids not fat and protein have been prepared, and these correlations are illustrated by graphs.

It is observed that the total ash falls with the solids not fat until low values of solids not fat are reached, when the ash content appears to rise. This variation is confirmed by a curve illustrating the variation in ash content of samples of individual cow’s milk. Soluble ash rises as the solids not fat falls, but the insoluble ash shows a reverse variation. Lime and phosphoric acid both fall with the solids not fat.

1. Under the extremely humid conditions obtaining in N. Wales, with soils showing a high degree of base-unsaturation, phosphoric acid applied to permanent grassland as basic slag is fugitive in its effect.

2. From profile analyses it is shown that after six to ten years added phosphoric acid is removed from the surface layers, which revert to their original phosphorus status.

3. It is suggested that the phosphorus of soils may be differentiated into that of the naturally occurring stable phosphates and the phosphorus of added dressings which is, under N. Welsh conditions, unstable and removable by percolating waters.

An account is given of an investigation of the alga-flora of four English soils by means of dilution cultures of freshly gathered samples of soil from the top, second, fourth, sixth and twelfth inch depths and from the top 6 in. mixed. A counting method is described applicable to the green algae and diatoms, by means of which it is shown that these algae are distributed throughout the top 12 in. of soil, though at the sixth and twelfth inch depths they are considerably less numerous than nearer the surface. At the fourth inch depth the numbers of individuals are not significantly smaller than on the surface and may be even greater.

The unmanured plot of Broadbalk wheat field was found to contain the same main species as the adjacent farmyard manure plot but was poorer in numbers of individuate. Thirty-five species are described from each plot; they seem to be divisible into two groups, the true soil forms and casual species. Of the true soil forms some grow equally well on the surface and in the lower layers, whereas others are more numerous on the surface than within the soil. The same main types were also obtained from Barnfield and from a cottage garden, but the blue-green species were less conspicuous in both of these soils.

Experimental evidence is given to show that many of the algae of the soil exist in a vegetative condition rather than a resting condition. Biological notes are made on some of the more important or interesting soil species.

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

(1) An aerobic coccus has been obtained from cultures of the motile butyric acid bacillus under conditions which exclude the possibility of contamination.

(2) Descriptions of the coccus and the bacillus are given.

(3) The coccus does not fix nitrogen in soil extract containing dextrose.