Wheat grain, by the processes of grinding and sifting, is resolvable into two distinct parts--bran and flour. In twenty-four analyses made by Boussingault, the proportion of the bran was from 13·2 to 38·5 per cent. and that of the flour from 61·5 to 86·8 per cent. The floury part is of very complex structure; it includes starch, gluten, albumen, oil, gum, gummo-gelatinous matter, sugar,[34] and various saline matters. The gluten and albumen constitute the nitrogenous, or flesh-forming principles of flour, and make up from 16 to 20 per cent. of that substance; the non-nitrogenous, or fat-forming elements, such as starch and gum, form from 74 to 82 per cent. According to Payen, the proportion of gluten diminishes towards the centre of the seed, from which it follows that the part of the grain nearest the husk is the most nutritious--so far at least as muscle-making is concerned. The desire on the part of the public for very white bread has led to the _fine_ dressing of Wheat-grain, and consequently to the separation from that substance of a very large proportion of one of its most nutritious constituents. Crude gluten may be obtained by kneading the dough of flour in a muslin bag under a small current of water; the starch, or fecula, and the gum, are carried away by the water, and the gluten in an impure form remains as an elastic viscous substance, which on drying becomes hard and brittle. It is to the gluten of flour that its property of panification, or bread-making, is due. On the addition of a ferment, a portion of the starch is converted into sugar and carbonic acid gas, and the latter causes the gluten to expand into the little cells, or vesicles, which confer upon baked bread its light, spongy texture. ANALYSES OF WHEAT. 1. 2. 3. 4. Whole Grain. Flour. Bran. Husk. Water 15·00 14·0 13 13·9 Flesh-formers 12·00 11·0 14 14·9 Fat-formers 68·50 73·5 55 55·8 Woody fibre 2·75 0·7 12 9·7 Mineral matter 1·75 0·8 6 5·7 ------ ----- --- ----- 100·00 100·0 100 100·0 _Nos. 1, 2, and 3.--The mean results of a great number of analyses._ _No. 4.--By_ MILLON.