It will be desirable, by way of preface, to say a word or two regarding the physical geography of the district, the soils of which form the subject of this paper.

Every farmer who feeds stock finds the necessity for supplementing his home-grown foods, which are usually of a bulky nature containing large proportions of carbohydrate and fibre, by purchasing concentrated foods rich in nitrogen and fat. Experience shows that it is by no means a matter of indifference which concentrated food is selected to mix with any particular bulky food, and the trend of modern physiological chemistry seems to point to a definite explanation of this fact. According to modern views, the protein eaten by an animal is split normally by the digestive ferments into amino-acids and other crystalline nitrogenous substances. It is in the form of such comparatively simple substances that the animal absorbs its nitrogen from the alimentary canal, and from them that it builds up its own characteristic proteins.

The general experience of breeders, supported by statistical evidence in the case of sheep, has shown that a good thriving, but not over-fat, condition during the breeding season is that which is most conducive to a high fertility. It has been shown further that the practice of “flushing” or “springing” ewes (i.e. artificially stimulating them by means of an extra supply of special food) shortly before and during tupping time results in an increased number of births at the succeeding lambing time. On the other hand, an excessive quantity of nutriment producing a great deposit of fat is known to be prejudicial to the proper discharge of the reproductive functions. No better example could be given of the way in which overfeeding results in a condition of sterility than that of the barren shire mares which have been a noteworthy feature at many agricultural shows. It is a matter for regret that those animals, whose appearance justified them as prize-winners, should in many cases have proved valueless as brood mares owing to the methods of feeding to which they had been subjected in preparing them for show. The association of sterility with a too fattening diet is as common among cows, sheep and pigs as it is among mares. Thus Cornevin writes: “Chaque aunée, dans les concours, nous avons sous les yeux des spécimens des plus belles races ovines et porcines qui, véritable modèles de bonne confirmation, de puissance assimilatrice et d'aptitude á prendre la graisse, restent stérile.” Moreover, Mr Edward Brown, the honorary secretary of the National Poultry Organisation Society, ascribes the decrease in egg production by poultry during the winter months in part at least to overfeeding.

A disease of swedes is described and attributed to the action of an organism, probably Bacillus oleraceae (Harrison), but closely allied to Pseudomonas destructans (Potter). It is suggested after consideration of its appearance on various culture media, that these two organisms may be different growth forms of the same parasitic species.

The value of soot as a manure depeuds upon the ammonium salts which it contains, as well as upon its beneficial effect on the texture and colour of the soil, and its power of diminishing the ravages of slugs and small snails upon a young crop. In various samples which from time to time have been submitted to analysis the percentage of nitrogen present has been found to vary within very wide limits, from 0·5 to 7 per cent., and it is usually stated to be present in the form of ammonium sulphate; actually it occurs for the most part as ammonium chloride.

Liver of sulphur, according to Thorpe, is an alchemistic term coming down to us from a time when there was no clear distinction between the alkalies, potash and soda. As a rule, the preparation was made from crude carbonate of potash, mainly for the reason that this substance was more easily procurable than soda. It was obtained “ by fusing in a Hessian crucible a quantity of potassium carbonate with half its weight of flowers of sulphur, and the fused mass poured out on a greased flagstone and allowed to solidify.” From the peculiar liver-brown colour the product derived its name.

Attention is drawn to the need for caution in interpreting experimental results.

Frequency curves are discussed, chiefly from the point of view of their bearing on the legitimacy of averaging results.

The method of calculating probable error is described and its meaning explained.

The application of probable error methods to questions of sampling for analysis, to field experiments and to feeding experiments, are illustrated by instances.

The probable error of one animal on a fattening ration is found to be about 14 per cent, of the live-weight increase produced, from which it is calculated that to obtain a precision of 10 per cent, in an ordinary feeding experiment 29 animals must be fed on each ration.

The probable error of field experiments is investigated by two independent methods, and found to be about 5 per cent, of the crop. This figure is shown to be independent of the size of the plot employed, provided this is acre or larger. A table is given showing the number of duplicate plots which must be employed to give any desired precision in the result.

It is also suggested that accurate results may be obtained by employing large numbers of very small plots, even as small as one square yard. This method is useful for nursery work in testing the cropping power of new varieties of cereals where very little seed is available.