1. In the comparatively humid climate, of the west of Scotland, the water content of oat grain, threshed soon after harvest, amounting, as a rule to between 16 and 18 %, fell, during storage, to between 12·0 and 14·5 %. Grain grown in the drier climate of the south of England and Wales contained on an average 12·2 % compared with 14·4 %. The weight of stored grain varied to a certain extent according to the hygrometric condition of the atmosphere. The maximum variation amounted to between 4 and 5 % of the initial weight of the grain.

In addition to the usual analytical data, it was found to be of great advantage, in connection with each sample of grain examined to keep a record of, date of threshing and date of analysis, proportion of whole grain, weed seeds, husk, etc., average weight of 1000 grains, height above sea-level, type of soil, length of growing period, rainfall, previous cropping and manuring, condition of the crop.

2. Between 11 and 12 % of the fatty substances in the oat kernel is present in the germ (embryo), the remainder is principally in the aleurone layer. The amount of extractable substances varied according to the solvent employed, ether and petroleum ether yielded the smallest and alcohol the largest extract. From 88 to 96 % of the total, was dissolved out by different solvents, in a five hour extraction. With repeated five hour extractions, ether still gave a small residue in the sixth extract. All the extracts contained finely divided solid matter in suspension, which could be made to separate out as a yellow residue and it amounted to between 0·25 and 6 % of the ether extract.

The extracts were found to be slightly higher from “air dry” meal and ordinary ether compared with “dry” meal and dry ether.

Free fatty acids were almost absent in the oil from freshly ground kernel, but afterwards they rapidly increased and in 24 days, calculated as oleic acid, they formed over 55 % of the extract. Drying the grain such as is done in the manufacture of oatmeal, had the effect of slowing down the rate of hydrolysis of the fat, but the amount of acid finally liberated was the same.

Even an amateur in agricultural science will admit that nowadays the fertilising effect of a substance cannot be tested merely by adding the substance to the soil and inspecting the resulting crop. This is not an experiment, it may give rise to an observation, but not to a conclusion. The production of the crop is connected with the fertilising process as a post hoc, not as a propter hoc.

Since the publication in 1914 of the results obtained by Daikuhara (2) in an investigation of certain acid soils of Japan, considerable prominence has been given in the literature of Soil Chemistry to the presence of iron and aluminium salts in the solution of sour soils.

“Silt”, like most insoluble substances, when suspended in water is most easily flocculated by calcium salts when the suspension is neutral. The addition of alkali stabilizes the suspension and renders flocculation more difficult. Soil “clay,” however, behaves in an opposite manner and is precipitated from alkaline suspensions more readily than from neutral suspensions. In this behaviour clay resembles silicic acid and some other members of the so-called “emulsoid” colloids, and it is suggested that the clay particles are protected by such colloids and thus behave as an “emulsoid” and not as a “suspensoid.”

If this is true then the action of lime, which being alkaline nevertheless flocculates clay, is seen to be in accordance with the facts of colloid chemistry.

The view is advanced and some experimental support of it is described, that clay, as an “emulsoid,” protects the larger particles which by themselves are “suspensoid.” The soil aggregates are conceived as having large nuclei surrounded by particles which become smaller from the centre of the aggregate outwards, the clay ultimately imposing its “emulsoid” nature on the whole aggregate, and on the whole soil in normal cases. Fine silt soils are not flocculated by calcium hydroxide on account of the inefficiency of the relatively small amount of “emulsoid” clay to protect the large “suspensoid” surface exposed by the fine silt.

The use of straw as fodder is beset by the double difficulty that on the one hand its bulky character seriously limits the extent to which it can be consumed by the animal, whilst on the other hand its tough and fibrous nature entails such a heavy expenditure of energy to secure the high degree of comminution and further preparation essential for effective action of the digestive agents that only a comparatively small surplus of energy remains over to serve productive nutritional ends. Thus it was found by Kellner and Köhler in the case of oat straw that of the total energy contained in the straw only 35·8 per cent, was usefully digested, whilst only 12·9 per cent, could be applied after digestion to productive purposes. For wheat straw the corresponding proportions were 31·1 per cent, and 5·5 per cent, respectively. These may be contrasted with the proportions of 49 per cent, and 20·7 per cent, respectively found by the same observers for meadow hay; and the proportions of 74·9 per cent, and 45·9 per cent, respectively found by Armsby and Fries for maize meal.

In connection with the experiments described in the foregoing paper the opportunity was taken of determining the digestibility of a proprietary product suggested for use as a feeding-stuff, which was made by subjecting finely-shredded peat moss to the action of hydrochloric acid gas, and subsequently expelling the latter from the residual product. By this treatment appreciable quantities of reducing sugars are produced in the peat moss, amounting in some cases, it is claimed, to 15 or even 20 per cent.