There is no unequivocal test for detecting in a _ready manner_ the presence of alum in bread, on account of the impurity of the common salt used in the making of bread. If we could, in the ordinary way of bread making, employ common salt, absolutely free from foreign saline substances, the mode of detecting the presence of alum, or at least one of its constituent parts, namely, the sulphuric acid, would be very easy. Some conjecture may, nevertheless, be formed of the presence, or absence, of alum, by assaying the infusion of bread in the manner stated, p. 109, and comparing the assay with the results afforded by an infusion of home-made or household bread, known to be genuine, and actually assayed in a similar manner. EASY METHOD OF JUDGING OF THE GOODNESS OF BREAD CORN, AND BREAD-FLOUR. Millers judge of the goodness of bread corn by the quantity of bran which the grain produces. Such grains as are full and plump, that have a bright and shining appearance, without any shrivelling and shrinking in the covering of the skin, are the best; for wrinkled grains have a greater quantity of skin, or bran, than such as are sound or plump. Pastry-cooks and bakers judge of the goodness of flour in the manner in which it comports itself in kneading. The best kind of wheaten flour assumes, at the instant it is formed into paste by the addition of water, a very gluey, ductile, and elastic paste, easy to be kneaded, and which may be elongated, flattened, and drawn in every direction, without breaking. For the following fact we are indebted to Mr. Hatchet. "Grain which has been heated or burnt in the stack, may in the following manner be rendered fit for being made into bread: "The wheat must be put into a vessel capable of holding at least three times the quantity, and the vessel filled with boiling water; the grain should then be occasionally stirred, and the hollow decayed grains, which float, may be removed. When the water has become cold, or in about half an hour, it is drawn off. Then rince the corn with cold water, and, having completely drained it, spread it thinly on the floor of a kiln, and thus thoroughly dry it, stirring and turning it frequently during this part of the process."[47] FOOTNOTES: [43] The sack of marketable flour is by law obliged to weigh 240 pounds, which is the produce of five bushels of wheat, and is upon an average supposed to make eighty quartern loaves of bread; and consequently sixteen of such loaves are made from each bushel of good wheat. It is admitted, however, that two or three loaves more than the above quantity can be made from the sack of flour, when it is the _genuine produce_ of _good wheat_; that is, in the proportion of about sixteen and a half loaves from each bushel of sound grain, and, it may be presumed, sixteen from a bushel of medium corn. The expense, in London, of making the sack of flour into bread, and disposing of it, is about nine shillings.