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Chemistry.—The five outer layers of the wheat grain are composed chiefly of cellulose, a woody, fibrous substance. The endosperm, the food part of the grain, contains large quantities of starch, a nitrogenous substance known as gluten, a little sugar, and the cellulose of its cell walls. The gluten content is greatest at the hard exterior of the endosperm. The softer center makes better flour, howevery for it remains freer from the bran in the grinding. The germ is composed of cellulose, nitrogenous substances, and about 10 per cent of fat.

The following table gives in per cents of the entire weight the comparison of different kinds and commercial grades of wheat, and of wheat straw and chaff.

comparisons of GRADEs of wheat, wheat STRAw AND CHAFF.

—i.

NitroKind of Wheat water | Ash | Pro olde gen | y, tein | Fiber | free | Fat extract

310 Amer wheats, min'....................... 7.1 0.8 8.1 0.4 64.8 1.3 310 Amer wheats, max! ...................... 14.0 3.6 17.2 3.1 78.6 3.9 310 Amer wheats, aver!...................... 10.5 1.8 11.9 1.8 71.9 2.1 Amer No. 1 hard?................................ ...I — 1.8 17.2 2.4 76.3 2.4 Amer No 1 northern?.......................... - 2.2 17.9 3.4 74.0 2.5 Amer No 2 northern?........................ - 2.2 18.3 3.2 73.9 2.3 Amer No 3 northern?............................! – 2.4 20.7 3.2 71.3 2.4 Minn No 163*........................................ 7.9 2.2 20.3 2.3 65.2 2.1 Rysting's Fife'.................................... 10.3 1.9 17.3 2.5 65.3 2.8 Bolton's Blue Stem”.............................. 9.3 2.0 16.6 2.5 67.2 2.3 Kubanka (durum wheat)*................... 16.5 2.2 18.9 2.5 57.3 2.7 Winter wheat, grain“........................... 14.4 2.0 13.0 3.0 67.6 1.5 Canada common wheat?...................... 10.9 1.4 12.8 2.0 70.4 2.5 Indian wheat, aver".............................. 12.5 1.7 13.5 2.7 68.4 1.2 Emmer kernels alone?.......................... 10.5 1.7 13.2 2.6 69.4 2.8 Emmer kernels and chaff?.................... 9.5 3.6 10.7 10.8 62.9 2.5 Emmer chaff alone............................... 6.4 10.5 2.6 37.9 4.1.1 1.6 7 Amer wheat straws, mini................ 6.5 3.0 2.9 34.3 31.0 0.8 7 Amer wheat straws, max! ............ 17.9 7.0 5.0 42.7 50.6 1.8 7 Amer wheat straws, aver'................] 9.6 4.2 3.4 38.1 43.4 1.3 Winter wheat, straw".......................... 14.3 5.5 2.0 48.0 30.2 1.5 Winter wheat, chaff'............................ 14.3 12.0 4.5 36.0 33.2 1.4 Durum wheat bran”............................. 10.9 5.3 12.3 10.8 54.9 5.9 Durum wheat shorts".......................... 10.4 4.1 14.4 6.1 59.2 5.9 Common wheat bran”.......................... 11.5 5.4 16.1 8.0 54.5 4.5 Common wheat shorts”........................ 11.8 4.6 14.9 7.4 56.8 4.5

1 U. S. Dept. Agr., Office Exp. Sta., Exp. Sta. Bul. 11, pp. 106-118. * N. D. Bul. 8, p. 6. Average results from many analyses. f ...Rept. N. D. Exp. Sta., 1903, p. 26. Data from N. D. wheat crop of 1901.

* Johnson, How Crops Grow, pp. 386-387.

* Rept. Canada Exp. Farms, 1900, p. 182. 1899 crop grown in the N. W. Terrs.

* Church, Food Grains of India, p. 95.

139 7 An average from Dak. Stations, U. S. Dept. Agr., Farm Bul. , D.

* Rept. N. D. Exp. Sta., 1904, p. 33.

The substances of which wheat flour is composed may be divided into three classes: (1) Nitrogenous, which include mainly gluten, fibrin, albumen, casein, cerealin, and modifications of some of these; (2) non-nitrogenous, embracing sugar and dextrin, but chiefly starch, fat and cellulose; and (3) the minerals, for the largest part alkaline phosphates and silicates, especially phosphate and silicate of potash.

WATER.—Wheat ordinarily contains from 10 to 15 per cent of moisture. Changes in the moisture content of the air cause corresponding variations in wheat, and consequently in its weight. Usually such fluctuations in weight do not exceed 6 per cent, but they may be as much as 25 per cent, and an increase of 9 per cent in 24 hours has been observed. When wheat is shipped, especially if it is transported long distances, this may be a matter of great commercial importance. Wheat transported from the dry atmosphere of the inland of California to ordinary temperate regions will invariably gain from 5 to 15 per cent in weight. In a voyage from San Francisco to Liverpool, the increase in weight due to the moisture absorbed en route may be sufficient to pay all expense of transportation. Every portion of the wheat grain is so susceptible to influence from hydroscopic conditions that all of the products of wheat exhibit similar oscillations in weight. Two days equalized the moisture content in samples of flour varying from less than 8 to over 13 per cent.”

AsH.-Lawes and Gilbert observed the composition of the ash of wheat grown on unmanured ground during 20 years. The average results are given in the table below.”

Grain Straw Ferric oxide . . . . . . . - - - - - - - - - - - - - - - - - - - - 0.645 0.69 Lime . . . . . . . . . . . . . . . . . . . . . . . . . - - - - - - - - 3.175 5.075 Magnesia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.48 1.525 Potash . . . . . . . . . . . . . . . . . . . . . . . . . . . ... .. 33.345 15.355 Soda . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.18 0.265 Phosphoric anhydride (PO") . . . . . . . . . . . 50.065 3.10 Sulphuric anhydride (SO’) . . . . . . . . . . . . . 1.42 3.84 Chlorine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.05 2.13 Silica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.655 68.505 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.015 100.485

1 Hunt. Cereals in Amer. (1904), p. 38; Mich. Bul. 191, p. 159-164. 2 Hunt, Cereals in Amer. (1904) p. 39.

Total . . . . . . . . . . . . . . . - - - - - - - - - - - 100.015 100.485
Deduct O-Cl ......... - - - - - - - - - - .015 .485
Total . . . . . . . . . . . . . . . . . - - - - - - 100.00 100.00

There is great uniformity in the ash constituents of the grain of wheat when it is not subject to irregularities in ripening, and there is but slight deviation under normal variations in soil composition.

PROTEIN.—Osborne and Voorhees' recognized and investigated five proteids. Approximately they form the following per cent of the grain: A globulin, 0.65; an albumin, 0.35; a proteose, 0.30; gliadin, 4.25; and glutenin, 4.25. Gluten is composed of several nitrogenous compounds, chiefly gliadin and glutenin. Wheat bread owes its excellence to the peculiar properties of gluten, which makes it lighter and more digestible than bread made from the other cereals. The amount and quality of gluten determine the baking qualities of a flour. It is now claimed that 55 to 65 per cent of the total gluten should be in the form of gliadin. Hard wheats have a higher gluten content than soft wheats, and consequently yield better flour. Gluten generally forms from 12 to 14 per cent of the wheat grain. Dough washed with water will retain only the crude gluten. A short growing period or a season unfavorable to full maturity of the grain increases the amount of protein. The nitrogenous compounds are the most desirable part of the nourishment found in wheat, but they tend to give a yellowish tint to the bread, ‘‘against which fashion rebels,’’ for the ‘‘unnatural demand of the times” is for a starchy, snow white flour.

NITROGEN FREE ExTRACT.-This forms the larger portion of both grain and flour, and is composed very largely of starch, the amount of which is easily influenced by the irregularity of seasons.

Composition Influenced by Seasons and Fertilizers.-A favorable season seems to give a high weight per bushel, a large percentage of starch, and a low ash and nitrogen content. The following table gives the results of the observations of Lawes and Gilbert at Rothamsted.”

1 Amer. Chem. Jour., 15:392-471. * Hunt, Cereals in Amer. (1904), p. 43.

Grain Grain Straw [Nitrogen Ash Wt. o: to per per in dry (pure) bu. lb. I straw acre acre matter in Per cent lb. lb. Per cent I mat'ro, Average of eight favorable harvests:

Plat 2—Farm yard

111a11ure.................. 62.6 62.5 2342 6089 1.73 1.98

Plat 3–Unmanu'd 60.5 67.4 1156 2872 1.84 1.96 Plat 10A–Ammo

nium salts alone. 60.4 66.2 1967 4774 2.09 1.74 Average of eight unfavorable harv's: Plat 2–Farm yard

ITlailure ................ 57.4 54.5 1967 5574 1.96 2.06

Plat 3—Unmanu'd 54.3 51.1 823 2433 1.98 2.08 Plat 10A–Ammo

nium salts alone 53.7 46.7 1147 3601 2.25 1.91

Composition as Affected by Light.—Light is essential for the formation of proteids. The following table shows the effect of differently colored glasses upon the nitrogen and albumen content of wheat."

Percentages of | Black Glass Green Glass No Glass Nitrogen 2.54 2.74 2.08 Albumen 15.87 17.12 13.00

Climate, soil and culture are also all factors that affect the chemical composition of wheat. They are treated more fully in subsequent chapters.

The Composition of Different Commercial Grades of wheat shows that the amounts of protein and ash decrease as the grade of wheat becomes higher, while the nitrogen free extract increases. Differences in protein, gluten or gliadin content do not seem to be an adequate basis, however, for the commercial grading of wheat. The grading seems to be based rather on the relative yield of first quality flour. The greater the weight of the kernel and the weight per bushel, the higher is the grade of the wheat.

Historically there has been little change in the chemical composition of wheat. It seems likely that the wheat of ancient Egypt did not differ more in composition from modern wheat of the same variety than one sample of modern wheat frequently differs from another.

1 Sci. Amer., 93 (1905): 508.

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CHAPTER II.
IMPROVEMENT OF WHEAT.
INSTITUTIONAL EVOLUTION.

Early Significance.—The culture of wheat has perhaps never been exclusively the subject of individual effort, but has also always been the subject of institutional essay, however vague and remote. Since the latter phase of wheat growing became scientific in the nineteenth century, it has been fraught with a significance of the widest and deepest interest. From an institutional point of view, the growers of wheat are not sufficiently differentiated from the agricultural element of society to warrant a distinctive treatment as a class proper. Only by a statement of such characteristics of the agricultural class as are apropos for a consideration of the institutional development relevant to the culture of wheat can the subject be approached.

By proverbial repute, the tillers of the soil are, comparatively speaking, independent, unprogressive, non-co-operative, and without marked tendency toward organization. Historically, they have been the last great class to be brought under a progressive regime of societal institutions. There are two main causes for this, neither one of which is inherent in the class. The first and fundamental cause is that agriculture is an occupation in nature and conditions such as to require isolation of those engaged in it, with comparatively little division of labor among them. It is an industry as broad as the land upon which it takes place, and admits of no concentration. On the other hand, taking the number of people adequately supported on a given area as a test, the industry is universally developed by a decrease in the size of the holdings of each individual, and by the diversification of labor consequent to this decrease. The second cause, more remote and less important than the first, is that in agriculture the influence of competition is necessarily indirect, and under certain conditions entirely inoperative. In civilized life competition in one form or another has

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