1. The free air in the pores of the soil to a depth of 6 inches is very similar in composition to the atmospheric air but it differs in two respects:

(a) It contains more CO2 and correspondingly less oxygen, the average in 100 volumes being 0–25 volume CO2 and 20–6 of oxygen against 0–03 volume CO2. and 20–96 oxygen in atmospheric air.

(b) It shows greater fluctuations in composition.

Usually the sum of the CO2 and oxygen is only slightly less than in atmospheric air but at periods when nitrates rapidly increase there is a perceptible falling off of oxygen, and a still greater one in waterlogged soils.

In a recent volume of the Journal of the Royal Agricultural Society of England, Russell deals with some of the effects of climate, and weather on soils.

1. The formation and translocation of the sugars in the mangold have been studied under actual conditions of growth, in which translocation was normal.

2. Starch is entirely absent from the leaf after the very earliest stages of growth. As soon as the root begins to develop so that the sugars formed in the leaf can be translocated to it, starch disappears almost entirely from the leaf. Maltose is entirely absent from leaf, mid-ribs and stalks at all stages of growth and at all times of night and day.

3. During the early stages of growth of the mangold, when leaf formation is the principal function, saccharose is present in the leaf tissue in excess of the hexoses. Later in the season, when sugar is being stored in the root, the reverse is true, hexoses largely predominating in the leaf.

4. In the mid-ribs and stalks the hexoses always predominate greatly over the saccharose and vary widely in amount during the day and night, and throughout the season, whilst the saccharose remains practically constant. In passing from leaves to mid-ribs, from mid-ribs to the tops of stalks and from the tops of stalks to the bottoms, the ratio of hexoses to saccharose steadily and rapidly increases. As the season advances the predominance of the hexoses in leaf, mid-ribs and stalks becomes more and more marked.

Within the last two or three years the attention of the agricultural world has been directed to the importance of the correlation of the chemical and physical properties of soils with the crops and systems of agriculture which farmers have found most suitable to them.

The work discussed in this paper is a continuation of that described in a previous communication to the Centralblatt für Bakteriologie. Unfortunately it has been found impossible to bring all the problems taken up to a satisfactory conclusion in the time available. And as, owing to unforeseen circumstances it is necessary, for the present at least, to leave this subject, the results so far as they have been arrived at are brought together in this publication and the lines on which it had been intended to work are indicated. It is hoped, however, that an opportunity of continuing this work on the soil Protozoa may present itself at some future date.

In an earlier issue of this Journal, Robinson and Halnan have communicated the results of a statistical analysis of three sets of pig-feeding experiments from which they conclude that “the probable error of one animal in a pig-feeding experiment is in the region of 10 per cent, of the average live-weight increase.”

1. It is shown that in the extracts of mangold leaves and stalks optically active impurities are always present which are not precipitated by basic lead acetate and hence vitiate the estimation of the dextrose and laevulose. These substances are possibly acid amides (such as glutamine and asparagine) or amino-acids (such as glutamic and aspartic acids) which form soluble lead salts.

2. These impurities occur in the leaves, but are much more abundant in the mid-ribs and stalks.

3. In the leaves the dextrose and laevulose appear to be present in approximately equal amount, as would be expected if they were formed from saccharose by inversion. When the ratio departs from unity it is probably owing to the presence of a dextro-rotatory impurity (glutamine?) which increases the amount of dextrose apparently present; but at certain times of the day a laevo-rotatory impurity seems to predominate so that the ratio becomes less than unity.

Kernel volume, because of its relation to the ratio of endosperm to non-endosperm structures, varies directly with the potential flour yield when comparisons are restricted to the same type or variety of wheat.

Accurate determination of kernel density must include the complete removal of all mechanically held air.

1. In the potato leaf when the tubers are beginning to develop the principal sugar present is saccharose; its amount increases from sunrise up to 2 p.m., following approximately the curve of temperature. It then falls during the rest of the day and night. The rise and fall are both linear.

2. The hexoses are present in the leaf in very small amounts—generally less than 1 per cent, of the total dry weight of the leaf. They fluctuate considerably during the early part of the day, the fluctuations being apparently determined by conversion into or formation from starch.

3. During the early part of the day up to 2 p.m. the proportion of starch changes very little, the small fluctuations which occur being related to changes in the starch. The starch is apparently formed from the hexoses.

Some discordant results obtained in mechanical analysis during a spell of cold weather led the writer to enquire into the effect of temperature on the separation of the various fractions of a soil by mechanical analysis.

In the early part of the present year the suggestion was made to me by my friend Mr J. C. F. Fryer that I should carry out a series of experiments designed to test the fly-breeding capacity of the open farm manure heap as distinguished from heaps in close proximity to dwellings.

The experimental results described in the two parts of the paper may be summarised thus:

Part I. Lime Requirements for Sterilisation Purposes.

(1) The capacity to produce partial sterilisation effects is a property belonging to calcium oxide (caustic lime), but not to calcium carbonate (chalk, limestone, marl, etc.).

(2) The amount of lime necessary to produce specific effects in different soils has been found to vary greatly and it is not possible to make any general recommendations.

During the last three or four years, the protozoa of the soil have been the object of a considerable degree of interest, and investigations into their occurrence and importance have been made by workers here and elsewhere. The aim of the present paper is to indicate what we know of the life of the protozoa in the soil, and to furnish descriptions of certain methods which have been found useful in work on this subject.

Most of the soil investigations in this country have been conducted at Rothamsted or other parts of South Britain and the soils examined have been chiefly those overlying the stratified rocks of the southern half of England. These, however, are by no means typical of the whole of Britain and research is needed into soils found extensively in Scotland and other parts of Britain which differ greatly in their origin, nature and properties from those which have hitherto been the chief subjects to which British investigators have devoted attention. The various agricultural colleges are taking up the study of the soils of their respective districts, and when the Farm of Craibstone was acquired as an Experiment Station by the North of Scotland College, a series of soil investigations was immediately commenced.

The following paper records experiments made to determine the magnitude of the error involved in the sampling of a soil for survey purposes. While it is not held that the results obtained are true for all localities, they serve to indicate the order of magnitude of the various errors.

One of the most common complaints of users of palm nut kernel cake is that it is liable to become rancid on keeping. Rancidity developing in an oil-seed residue like palm nut kernel cake is likely to be due to splitting of the fats of the cake by a fat-splitting ferment or enzyme— a lipase—formed under certain conditions. The resting seeds do not contain lipase, but they are likely to contain a zymogen from which under suitable conditions lipase is formed.

Owing to the rapid rise in the price of linseed and linseed products during recent years, the question has arisen as to whether the farmer can grow linseed, for home consumption, at a smaller cost than he can buy it for under existing conditions. This question involves considerations as to which of the several kinds of linseed would be the most profitable to grow, and it becomes necessary to consider not only the agricultural requirements of the crop, but also the fact that the value of this crop is largely, if not entirely, determined by the quantity of oil produced per acre.

The account given by Wood and Yule of their investigation of the records of British Feeding Trials and the Starch Equivalent Theory in part 2 vol. VI of this Journal is a valuable and timely paper. It contains abundant material for reflection. Consideration of the data suggests that there is room for doubt in regard to the conclusions for which a claim to “certainty” has been advanced. It is not, however, the immediate purpose of this article to discuss these conclusions—though incidentally certain points in the investigation come under review—but rather to discern, as far as possible, the direction in which the methods and arguments employed lead, and more particularly what is their bearing on the starch equivalent theory as a practical system.

The object of the experiments described below was to establish, more clearly to what the fungicidal value of alkaline sulphide solutions is to be attributed.