Page:Encyclopædia Britannica, Ninth Edition, v. 3.djvu/267

Kent, and in some parts of Lancashire. In the year 1804 the town of Manchester, with a population of 90,000 per sons, did not contain a single public baker. Bakers in Great Britain are now placed under the provisions of " The Bakehouses Regulation Act, 1863" (26 and 27 Viet. cap. 40), a statute passed after a searching inquiry into the condition of bakehouses in London and of the persons employed in them. By this Act no young person under the age of 18 is permitted to work in a bakehouse between the hours of 9 P.M. and 5 A.M., and special enactments provide for securing the cleanliness and ventilation of bake

houses, and for the regulation of sleeping apartments connected with them.

As compared with wheat-flour all other materials used for making bread are of comparative insignificance. Oat cakes still form a staple article of food in many rural dis tricts of Scotland, and are occasionally used in other coun tries. They are made by mixing up oatmeal, warm water, and salt, sometimes with the addition of butter or fat, into a very stiff paste, and kneading this out into a thin cake, which is first fired on a hot plate or " girdle," and finished in front of an open fire. Scones of barley-flour, sweet and tough, were formerly largely used in Scotland, but have now given place to a similar preparation of wheaten flour. Rye bread, both fermented and unfermcnted, is largely con sumed by the inhabitants of the northern parts of Europe in the poor and backward districts. Cakes of maize meal, baked like oat cakes, are consumed in some parts of the United States. The meal of various species of millet is used in Southern Europe to form bread ; and in India and China, durra (Sorghum vulgare) and other cereal grains are baked for food. Of non-cereal flours, the principal used for bread-making is buckwheat. Fagopyrum escu- lentum, extensively employed in Russia and Holland. The flour of pease, beans, and other leguminous seeds, are also baked into cakes ; and cassava cakes are made from the meal of the tapioca plant, Jatropha Mani&ot, in South America. Excepting rye, none of these substances is used for making vesiculated or fermented bread.

The grain of wheat consists of an outer husk or cover ing, an embryo or germ, and a central mass of farinaceous material. The outer husk is composed of several distinct layers of ligneous tissue, closely adhering to the seed, and very hard in texture. In grinding, this is detached in scales, and constitutes the chief proportion of the bran. The inner portion of the envelope is softer, and contains an active nitrogenous principle, termed cerealin, and is besides rich in fat and salts. This portion goes with the pollard or parings in the dressing of wheat flour. Towards the centre of the grain the substance becomes whiter in colour and more friable in texture, so that, in grinding, the finest flour in consistence is always the whitest in appearance. By agriculturists several hundred varieties of wheat and a number of distinct species are recognised; but in com merce the grain is distinguished as white and red, or aa hard and soft wheats. There is a considerable range of difference in the proportions of their proximate constitu ents, hard wheats as a rule being much mora nitrogenous than the soft varieties ; and similarly, wheats grown in hot climates are also usually richest in nitrogen. The follow ing analyses of two typical varieties of wheat are taken from Payen s tables, water being neglected:—

Hard Wheat. Soft Wheat. Taganrog. Touzelle. Nitrogenous matter 20 00 12 65 Starch 63 80 7-151 Dextrin S OO 6"05 Cellulose 3 10 2 80 Fatty matter 2 25 l S7 Mineral matter 2 85 2.12 Wheat of 1846. 7 Cases. Wheat of 1847. 19 Cases. Wheat of 1848. 2 Cases. Mean of the 28 Cases. 1. Wirel 44-0 357 47-4 411 2. Wire 2 17-9 16-4 23-9 18 6 3. Wire 3 8-7 13-3 2 9 2 Amounts of 1, 2, and ) 3 together $ 69-3 70-2 73-3 70-2 i 4. Tails 4-9 5-3 21 5 3 I 5. Fine Sharps or Middlings 10-2 8-7 4-5 8-8 6. Coarse Sharps 3 5 3-3 3-6 3-4 j 7. Fine Pollard 3-9 1-8 2 6 2-4 1 8. Coarse Pollard 4 4 7 2 7-9 6-5 9. Long Bran 3 5 2-5 5-9 3-0

When wheat is ground it is sifted or dressed into a series of mill products, ranging from fine flour to bran, according to the size of the ground particles. The divisions vary in different mills and localities ; but the accompanying table the result of an elaborate series of experiments by Messrs Lawes and Gilbert may be regarded as a standard of the relative proportions of mill products:—

Mean Yield of Flour, Bran, <L-c., in 100 parts Meal.

The tails and fine sharps are generally passed through the mill a second time, bringing up the yield of flour to about 80 per cent, of the entire grain. As an example of mill products in practice, the following table is copied from the actual mill receipts of a Scotch miller. The quantity dealt with represents 16 quarters of wheat, weighing 63^ It) per bushel, in all 578 st. 115). The yield was—

st. rb Fine Flour 414 Odd and Second Flour 23 13 Parings (Sharps and Pollards) 36 12 Bran and Shellings 92 Waste 11

The composition of flour and bran given in the under stated table is the mean result of a series of fourteen analyses by Peligot:—

Flcnr. Bran. Water 14 10 SO Fatty matters 1 2 2 82 Nitrogenous substances insoluble in water (gluten) ...12 8 10 84 ,, ,, soluble ,, (albumen) ] 8 T64 Ken-nitrogenous soluble substances dextrin, sugar, 7 2 5 80 Starch 597 22 62 C ellulose 1 7 43 98 Salts 1-6 2-52

It is a disputed point whether dextrin or sugar exists in flour of the best quality; but the action of heat and mois ture in the baking process quickly transforms a portion of the starch into the soluble condition. In flour of inferior quality a large percentage of dextrin is usually found a circumstance very detrimental to its bread-making qualities. A table of the percentage of gluten, obtained by Messrs Lawes and Gilbert from a large number of flours, shows a variation from 8 9 to 14 9 per cent. This gluten itself (tbe insoluble nitrogenous substance in flour) is a compound body, composed of three or four distinct substances ; but its physical conditions of elasticity, tenacity, and colour are of much greater importance to the baker than either its chemical constitution or its amount.

The varieties of wheaten bread are divisible into two great classes Unvesiculated and Vesiculated Bread. Under the first head are included such products of the art as are fired or baked without first being raised or rendered spongy by the development of carbonic acid gas within the mass, either by fermentation or otherwise. Vesiculated bread is produced when carbonic acid is either developed in or introduced into the dough, so as to per meate the mass with an infinite number of minute cavities, which render the product light and spongiform.