Adult. The adulteration of both flour and bread is carried to a fearful extent, more especially in London. The baker’s flour is very often made of the worst kinds of damaged foreign wheat; and other cereal grains, and particularly beans, are mixed with them in grinding them into flour. In this capital no fewer than six distinct kinds of wheaten flour are brought into the market—fine flour, seconds, middlings, fine middlings, coarse middlings, and twenty-penny flour.

Among the principal substances which have been proved to have been used to adulterate wheat-flour and bread are the following:—

**Alum.
*Ammonia (Sesquicarbonate).
**Beans.
*Bone dust.
*Chalk.
Clay.
Copper (Sulphate).
Lime (Sulphate from the soda water makers).
*Magnesia (Carbonate).
*Plaster of Paris.
*Potash (Carbonate and bicarbonate).
**Potatoes.
**Rice.
**Soda (Carbonate and sesquicarbonate).
*Starch (Potato).
**Water (in excess).
Zinc (Sulphate).

Of these substances, those marked thus (*) are very frequently used; and those marked thus (**) almost universally so.

In the absence of chemical analysis the unalumed loaf may be roughly distinguished from the alumed one by the following characteristics: it is neither so white, so bulky, nor so symmetrical; it bites shorter, and it is free from the sour taste which accompanies the presence of alum. Again, unalumed bread a day or two old will be found to crumble with great readiness; alumed bread, however old, crumbles, on the contrary, with difficulty.

According to Mr Accum, the smallest quantity of alum that can be employed with effect to produce white, light, and porous bread, from the inferior kinds of flour commonly used by the bakers, is from 3 to 4 oz. to a sack of flour weighing 280 lbs. But Dr P. Markham states that the ordinary bread of the London baker is made of one sack or 5 bushels of flour; 8 oz. of alum; 4 lbs. of salt; 1⁄2 gall. of yeast; and about 3 galls. of water. Our own analyses, extending to many hundred samples of London bread, as well as those of other chemists, show that even this large quantity of alum is often very much exceeded by the bakers.

Alkaline substances, as the carbonates of ammonia, soda, and potash, are often employed to realise the important consideration of producing light and porous bread from spoiled, or, as it is technically called, sour flour. The first salt becomes temporarily converted into a gaseous state during the operation of baking, causing the dough to swell up in minute bubbles, which thus render it light and porous; the salt itself being at the same time, for the most part, volatilised. Alum is added, not only with a like intention, but also to enable the dough to carry more water. There are several instances of convictions on record of millers and bakers having used gypsum, chalk, and pipeclay in the manufacture of their goods. A gentleman lately writing from the

North of England says that he found in one sample of flour which he recently examined upwards of 16% of gypsum; and in another, 12% of the same earth.

A few years since it was discovered that some of the bakers in France and Belgium added blue vitriol to their dough to make it take more water, in the same way as the English baker uses alum. 1 oz. of this sulphate was dissolved in a quart of water, and a wine-glassful of this solution added to the water necessary to make about 50 4-lb. loaves. This enormous crime was soon detected, and deservedly caused the ruin of its heartless perpetrators.

Exam. The following are the methods employed for the discovery of the principal sophisticants of bread, and as the chief of these, and the one most difficult of identification is alum, we have given prominence to the processes now generally adopted for the detection of this article:—