The following résumé of the work so far published by the Home-grown Wheat Committee of the National Association of British and Irish Millers is based upon a paper presented by one of us to the International Convention of Millers which met in Paris during October, 1905. This work being well past the tentative and preliminary stages it proved possible to make a broad survey of it and to piece together isolated special portions which have been published from time to time.

1. All determinations of soil moisture should be made to a depth of from four to five feet for wheat and oats, and to a depth of six or seven feet for grasses.

2. Unless all the soil under consideration is very uniform, determinations of the hygroscopic coefficient are indispensable. The determination of this value is extremely important even where the soil is uniform.

3. The storage capacity for available water of the two soil types studied, may be placed at from five to seven inches of rainfall for wheat and oat crops.

4. A better idea of the moisture conditions of the soil at Indian Head may be obtained from a casual examination in the field than from the drying and weighing of the samples, unless the hygroscopic coefficient is considered.

5. The moisture stored in the subsoil during the previous summer, and not the frost of the preceding winter, is the cause of the high yields of wheat and oats obtained in southern Saskatchewan.

6. The soil of southern Saskatchewan does not remain permanently frozen at any depth.

7. Investigations of the moisture conditions to a depth of only 12 to 16 inches are of no value and may often be entirely misleading.

On crossing immune and susceptible varieties the resulting offspring is susceptible.

On self-fertilization these susceptible individuals produce immune and susceptible descendants in the proportion of one of the former to three of the latter. The degree of susceptibility is variable.

Where the degree of susceptibility differs in the two parents the hybrid resembles the more susceptible parent in that respect. Among the descendants of such hybrids the two degrees of susceptibility appear in the usual Mendelian ratio of one slightly to three very susceptible individuals.

The relatively immune forms breed true to this characteristic in the succeeding generations.

Immunity is independent of any discernible morphological character, and it is practicable to breed varieties morphologically similar to one another, but immune or susceptible to the attacks of certain parasitic fungi.

It is well known that the mean temperature falls as the elevation increases, and partly on this account certain crops cannot profitably be produced on high land. But it is also recognised that low lying land is subject to lower minimum temperatures, and is therefore more liable to frost, than land higher up, and low situations are consequently avoided by fruit and early potato growers. Few actual temperature readings have, however, been published.

It has been known for a long time that there exist varieties of wheats and other cereals which appear to be practically free from, or immune to, the attacks of certain fungal parasitic pests, by which closely allied forms are ravaged.

In experimentally infected birds a clear viscid discharge from the nostril is sometimes the first symptom noticed, and may occasionally be the only one for a long time (turkey E). This is followed by a soft fluctuating swelling under one or both eyes. After the development of a well-marked swelling, the course of the disease may vary both in naturally and experimentally infected birds. In some cases the swelling gradually diminishes and finally disappears (turkeys 3, C, D, F, and G), in other cases the soft fluctuating swelling persists for considerable periods (turkeys 1, E and H), and in others the swellings become hard and the gelatinous contents are replaced by cheesy, foulsmelling material (turkeys 2, A and B). The latter condition may be due to secondary infection. Sometimes the disease only attacks one side leaving the other quite normal. Death occurred in some instances, but could not be definitely attributed to the disease.

It has been shown that many rocks, when samples are taken from such a depth as precludes all possibility of weathering, contain nitrogen in amounts comparable to those present in soil, especially when the strata consist of indurated clays like the Lower Lias, Oxford, Kimmeridge or London Clay. Since the rocks also contain carbon the nitrogen is without doubt of organic origin; the carbon and nitrogen compounds represent the humus present in the clay when it was deposited, and are in fact the mineralised remains of that organic matter. When soil is produced by the weathering of such rocks these carbon and nitrogen compounds will remain wholly or in part in the soil and may there account for a considerable proportion of the total nitrogen they contain. It thus becomes of some importance to ascertain if this nitrogen is ever likely to become available for the plant by the normal processes of bacterial oxidation, or whether it has passed into such a state of combination as to be susceptible of no further change under such conditions as prevail in the soil. If the compounds are too mineralised or bituminised to be attacked by bacteria it would explain the fact that much of the nitrogen present in soils seems to remain permanently beyond the reach of plants. For example the soil of Broadbalk wheat field at Rothamsted, which had been cropped continuously with wheat for 50 years without the addition of any manure, still showed in 1893 very nearly 0·1 per cent. of nitrogen, equivalent to about 2500 lbs. per acre in the top 9 inches of soil; yet the average wheat crop on this plot only contains about 17 lbs. of nitrogen, of which 5 lbs. is supplied annually by the rain, without taking into account any further additions by the action of Azotobacter and kindred organisms.

In February 1905 I made a short communication to the Royal Society of London (Proceedings, Vol. Lxxiv. page 562), upon an apparent relation between the yield of wheat for England in the 21 successive years 1884 to 1904 and the aggregate rainfall for the three autumnal months (September, October, November) of the preceding years of the principal wheat-producing districts of Great Britain. The relation was put into the algebraical form:

It has long been recognised that a trace of soluble salt will bring about the flocculation of the material suspended in a turbid liquid; and because of its bearing upon such practical matters as the clearing of drinking water, the deposition of silt at the mouths of estuaries, and the improvement of the texture of heavy soils, the process has received a considerable amount of investigation. It is probably related to the flocculation of colloids by similar reagents; the fine particles of clay which chiefly cause the turbidity of natural waters being composed of a hydrated silicate of alumina and other bases possessing properties akin to those of the colloids. Indeed Schloesing has proposed to call that portion of clay material which remains obstinately suspended in water, sometimes for days together, ‘colloid clay,’ as something distinct in kind from the other particles in the soil. However it is reasonable to suppose that the distinction between the ‘colloid’ clay and the rest is in the main one of size, the colloid particles being so small as to be beyond the limits of microscopic vision, just as the trae colloids may be regarded as consisting of very large molecules, lying between the molecules which go into solution and the molecular aggregates that remain in water as suspended solids.

The Khedivial Agricultural Society of Egypt recently voted a capital expenditure of £2000 towards the establishment of a Mendelian Experiment Station for the study of heredity in cotton.

DR Miller's interesting and important paper in the last number of this Journal (Vol. I. p. 377) raises several points in connexion with the long-continued action of rain on uncultivated and uncropped soils.

Attention is drawn to the complexity of the ideas comprised in the term strength as applied to flour, and the necessity of investigating each idea separately.

The chemical composition of the gliadin and glutenin of strong and weak flours has been investigated, and it is shown that they are identical in all the flours examined. It is suggested therefore that the difference between strong and weak flours is connected rather with the physical properties of their gluten than with the chemical composition. Since it is well known that the physical properties of proteids are profoundly affected by small quantities of acids, alkalis, and salts, the amounts of these substances in strong and weak flours were determined. In the few cases examined, it was found that strength was associated with a high ratio of proteid to salts, and weakness with a low ratio. It is suggested that the variation of this ratio may be the explanation of the different physical behaviour of the gluten of strong and weak flours, and that this is the factor which determines that component of strength which governs the shape of the loaf, and its power of retaining gas. This point is receiving further investigation.

The factor which primarily determines the size of the loaf which a flour can make is quite distinct. The size of the loaf is shown to depend in the first instance on the amount of sugar contained in the flour together with that formed in the dough by diastatic action. It is proposed to measure this by incubating the flour with yeast and water, and collecting the carbon dioxide evolved during 24 hours. Particular attention should be paid to the rate of gas evolution in the later stages of the fermentation, as this is shown to be more directly connected with the size of the loaf.

Taking Humphries and Biffen's definition of strength as “the capacity for making large well-piled loaves,” and applying the above ideas, it is stated that the largeness of the loaf depends chiefly on the capacity of the flour to give off gas when fermented with yeast, especially in the later stages of dough fermentation, and the suggestion is made that shapeliness, and probably gas retention, are dependent on the physical properties of the gluten as modified by the presence of varying proportions of salts.

In 1904, Sir James Blyth, Bart., a member of the Cambridge University Board of Agricultural Studies, offered a Scholarship tenable by a student who had taken the University Diploma in Agriculture, for the purpose of enabling him to spend a year in research. The offer was gratefully accepted, and the Scholarship was awarded to Mr F. W. Foreman. Mr Foreman submitted as a subject for investigation the Composition of certain of the Soils of Cambridgeshire. This subject was approved, and the work was carried out in the winter months of 1904—1905. The results are given in the following pages.

Ten grams each of the manures Sulphate of Ammonia, Nitrate of Soda, Calcium Cyanamide and Nitrate of Lime (Notodden, 1906) were exposed to air in a room the windows of which were kept open during the experiment, and the changes in weight noted for a period of twenty-nine days. At the same time Barometric and Temperature (Wet and Dry Bulb) readings were taken daily.

In some of the earlier experiments in which Bordeaux Mixture was used as a fungicide, it has happened that neither the part sprayed nor the control has suffered from disease at all; yet it has been recorded that the sprayed part has continued green for a longer period and has produced a larger crop.

Some years before the appearance of Hellriegel and Wilfarth's work on the sources of nitrogen of leguminous plants, and while the part played by atmospheric nitrogen in the nutrition of crops was under active discussion, Berthelot was making some exact observations on the behaviour of uncropped soils towards the free element. He found that when 50 kilograms of air-dry arable soil were exposed to the air and rain in a vessel for seven months a great increase in the nitrogen content could be observed; the total nitrogen of the original soil had increased from 50 grams to 63, or a gain of over 25 per cent, after allowing for the small amount of combined nitrogen brought down by rain; in another experiment where the soil had first been washed free from nitrates, a gain of 46 per cent, of nitrogen was proved. In many other cases, however, the gain was only from 10–15 per cent, of the original nitrogen present in the soil.

It is now a well-established fact that the ammonia, which is formed in the cultivated soil by the breaking down of nitrogenous organic matter through the action of bacteria and moulds, is itself converted by oxidation into nitrates. The latter process, “nitrification“ proper, is effected in two stages by two distinct species of bacteria, the one carrying the oxidation to nitrite, and the other changing the latter compound into nitrate. It is also known that, in the absence of a base, nitrification does not take place. The most usual and most available soil base is calcium carbonate, which is, however, present in some arable soils to only a very small amount, less than ·05 per cent.; in such soils, and in others where its presence cannot be detected, nitrification is still active, a fact which seems to suggest that other substances may replace it and serve as bases for nitrification.

The following experiments on the hybridisation of barley were commenced in 1901; consequently the inheritance of some of the characteristics has been known for some time. In view of the fact that from the earlier accounts of Rimpau and Tschermak the main outlines of the story could be traced without any special difficulty, there appeared to be no necessity for immediate publication. This was delayed, therefore, in order to complete the investigation of one or two doubtful points. The literature of barley-breeding published prior to the year 1900 is rather extensive, but of comparatively little interest to the modern student of heredity. The most important papers are those of Liebscher and Rimpau. That part of Rimpau's great paper, “Kreuzungprodukte Landwirtschaftliche Kulturpflanzen,” dealing with barley, is of exceptional interest on account of its extreme thoroughness and the completeness of the records it contains. As one reads it one cannot help thinking that Rimpau must have come very near to making an independent discovery of Mendel's laws of inheritance.

Before proceeding to discuss the immediate subject of this communication, it may be well to recapitulate shortly the views on the general question of the meaning of strength of flours which I expressed in the last number of this journal. It may perhaps be remembered that I suggested that strength, as defined by Humphries and Biffen, to be the capacity of making large well-piled loaves, must be a complex of at least two factors. One of these factors, that which regulates the size of the loaf, I showed to be the power of continuing to evolve carbon dioxide gas throughout the later stages of dough fermentation. I described how to measure this property by incubating in a bottle at 40ºC. a mixture of 20 gms. flour, 20 c.c. water, and ½gm. yeast, the bottle being connected to a gas measuring apparatus, and the volume of gas given off being read from time to time. A number of experimental figures were given, which showed that the size of the loaf which a flour could make, was directly connected with the rate at which it gave off gas in the later stages of dough fermentation, at the time when it was ready for the oven.

The process of making silage is an ancient one and the scientific investigations date back at least to 1873, when Weiske, at the Proskau experiment station, showed that there was a loss of carbohydrate, fibre and protein in making silage from sainfoin and other crops. It was, however, by no means general till after the publication in 1875 of Goffart's remarkable success with maize silage at Burtin, in the barren district of Sologne (Loire-et-Cher). Both Grandeau and Barral analysed Goffart's silage, the former noted the production of volatile and non-volatile acids and labelled them acetic and lactic acids respectively, in which practice he has been followed by most later analysts. Five years later Kellner demonstrated by careful quantitative measurements that the decrease in protein was accompanied by an increase in the amount of ‘amide’ nitrogen. In his experiments about 28 per cent. of the nitrogen was lost, but in a subsequent paper this was traced to volatilisation of ammonia during manipulation of the sample. Kellner considered, and probably correctly, that no nitrogen is lost in the free state from the silo.