The ammoniacal nitrogen in the Rothamsted rainwater amounts on an average to 0·405 part per million, corresponding to 2·64 lb. per acre per annum. The yearly fluctuations in lbs. per acre follow the rainfall fairly closely. The monthly fluctuations also move in the same direction as the rain, but the general level is highest during May, June, July and August, and lowest during January, February, March and April (Tables 1, 2, 3, and Figs. 1 and 2).

The nitric nitrogen is on an average one-half the ammoniacal, viz., 1·33 Ib. per acre per annum. The amounts fluctuated year by year and month by month in the same way as the ammoniacal nitrogen and the rainfall until 1910, since when there has been no simple relationship (Tables 1, 2, 3, and Figs. 1 and 2).

Reasons are adduced for supposing that the ammonia arises from several sources. The sea, the soil, and city pollution may all contribute. Neither the sea nor city pollution seems able to account for all the phenomena: the soil is indicated as an important source by the fact that the ammonia content is high during periods of high biochemical activity in the soil, and low during periods of low biochemical activity.

Stems of Dactylis glomerata were collected from grass-plots which had received different manurial treatment as regards potash.

The yield of hay from these plots was in close agreement with the average which shows that the season during which the work was done was not abnormal.

The thickness of the wall, the diameter of the lumina and the ratio of the lumen to the wall were measured both in sclerenchyma and metaxylem elements.

It was found that in the early stages the sclerenchyma walls were thinner where potash had been supplied, but that this effect was lost as the season progressed.

The lumina were larger in plants which had received potash, when nitrogenous fertilisers had not been added, but in the presence of ammonium salts, this effect was reversed.

In the xylem the thickness of the walls was unaltered whether potassic fertiliser were added or not. When no nitrogenous manures were added the diameter of the lumen was decreased in the presence of potash, but when ammonium salts had been applied, the diameter was increased by the application of potassic fertilisers.

During the years 1908–1913 inquiries with reference to the infertility of soils were frequently received from farmers in various parts of Cardiganshire. Upon examination it was found that the primary cause of infertility in most of the cases was the presence in the soil of appreciable quantities of lead. At first it was thought that only a few isolated spots were thus affected. Further investigation, however, revealed the fact that a relatively large area of what should be naturally the best land of North Cardiganshire was suffering from the same cause, and that a considerable number of farmers were of opinion that both their soils and their live stock suffered from “lead poisoning.” Consequently, it was thought advisable to make a survey of the affected land and to investigate possible remedial measures.

Very diverse views are expressed on the height to which water can rise in soils under the forces of capillarity. Alway and MacDole in the course of a brief historical review, point out that these estimates range from two or three feet only, to as much as two or three kilometres, although the majority do not exceed 200 feet. Most of the investigators who advance a high value for the capillary rise are careful to point out that in all probability the movement of water in this case would be exceedingly slow, owing to the excessive friction in the minute capillary spaces. Actual experiments on the rise of water in tubes of compacted soil result in low values, which are in all probability exceeded in the field. Warington in his book Physical Properties of Soil gives a typical table showing the results of Loughridgeb for Californian soils.

An examination has been made of some of the extensive experimental data obtained by Bouyoucos and his associates on the freezing-point depression of soil solution at varying moisture contents, examined in situ.

These workers find that the soil solution in quartz sand and extreme types of sandy soil obeys approximately the same law as dilute solutions—the freezing-point depression varying as the concentration, or in the present case, inversely as the moisture content. In other words

where K is a constant, and Dn is the freezing-point depression, at a moisture content of Mn. Soils do not obey this law, the freezing-point depression rapidly increasing as the moisture content decreases.

Wherever the opium poppy is cultivated its seed forms a valuable secondary crop. India has a bigger outturn of seed than any other country. In the years immediately preceding the war the bulk of the poppy seed produced in India was exported. The following Table gives an idea of the proportion of the total production exported for a number of years past.

1. It has been shown that the direct counting method for soil protozoa devised by Kopeloff and Coleman for use in liquid media gives results entirely comparable with those obtained by a dilution method.

2. The factors governing the relation between the protozoa and the soil particles are those of surface action, and the capacity of various substances, sand, soil and clay, for retaining these organisms is specific and constant.

3. Coarse sand is capable of withdrawing per gram approximately 145,000 amoebae and flagellates per c.c. from a suspension of any strength. Fine sand withdraws approximately 980,000 per c.c: soil and partially sterilised soil 1,650,000, ignited soil 1,500,000 and clay 2,450,000.

4. These figures are constant for given material and organisms and are independent of the concentration of the suspension, the time of action, or whether the suspension contains cysts or active forms of the amoebae and flagellates investigated. Also the action is the same when the experiment is performed with a suspension of living or dead organisms.

5. Experiments with the ciliate—Colpoda cucullus—show that coarse sand per gram retains 27,000 per c.c.; fine sand per gram 185,000 per c.c; soil and partially sterilised soil 280,000 per c.c; ignited soil 270,000 per c.c. and clay 450,000 per c.c.