BREADSTUFFS 77 
lb. of wheaten flour, costing only 1d. The amount of external 
work that 1 lb. of bread will enable a man to perform is 267 tons 
raised one foot high, a fair day’s work for a labourer being 2 foot- 
tons per lb. of his body weight. The amount of dry muscle or flesh 
that can be produced from 1 lb. of bread is about 1{ oz. 
Wheat takes precedence of all other cereals as a bread grain, 
and this is chiefly owing to the glutinous nature of a large pro- 
portion of the albuminoids. When carbonic: acid gas is intro- 
duced into the dough, either by means of fermentation or aeration, 
the elastic gluten impedes the escape of this gas, and causes it to 
accumulate in bubbles; the innumerable small cavities thus 
formed in the dough are fixed by the heat of the oven, and the 
result is a light, spongy bread. Dough made from the other grains 
which lack this glutinous property will not rise properly, and 
therefore makes a heavy bread, or can only be made into cakes. 
The various processes of milling which the wheat-grain undergoes 
considerably modify the percentages above given, particularly in 
the modern roller mills where the operations of grinding and 
sifting are repeated many times in order to produce a snow-white 
and almost impalpable flour. During these operations, as will be 
readily understood on reference to fig. 40, numerous mill-products 
are obtained—fine and seconds flour, middlings, sharps, pollard 
and bran ; these products having each a different chemical com- 
position and food-value. In the production of the finest flour, 
this system of high milling eliminates every particle of the coats of 
the grain as well as the embryo. The removal of the embryo, 
because its presence would give a yellowish tinge to the flour, is 
unjustifiable ; this is the most nutritious part of the grain, the per- 
centage of albuminoids and diastase in the embryo being 35 ; oil, 
13 ; mineral matter, 5'5 ; more than half of the last-named being 
phosphoric acid, a nutrient of bone and brain. Asa result of milling 
wheat, 75 per cent. of white flour is obtained, and the offal (sharps, 
pollard and bran) amounts to about 23 per cent. Seconds flour is 
richer in nutrient matters than the finer grades, the latter containing 
2 per cent. less albuminoids than are present in the grain, and about 
5 per cent. more starch, while the percentage of oil and salts is in 
each case reduced to ‘8. Bread made from fine wheaten flour con- 
tains about 40 per cent. of water, 7 per cent. albuminoids, about 50 
per cent. starch, and 17 per cent. salts (including table salt). Whole 
meal, only the outermost coat of the grain having been removed, 
contains all the nutrients of the grain, but also a considerable 
amount of indigestible cellulose. A finely-ground flour, containing 
the embryos, but no portion of any of the coats of the grain (this is 
known in the trade as germ-flour), makes a perfect bread, well 
vesiculated, sweet, and with a delicate aroma; it keeps moister 
than bread made from ordinary flour, and is of course more 
nutritious. 380 lbs. of bread can be made from a 20 stone sack 
of flour. Macaroni is prepared from the horny wheats of Southern 
Europe; it is more highly nitrogenous than bread. Semolina 
consists of the coarse particles of the interior of the grain. The 
