There are two kinds of albuminoids, or gluten, present in wheat—one insoluble, the other soluble in alcohol. The former makes what is called a ‘strong bread,’ and the latter acts, in bread-making, on the former, and, under the influence of yeast, it attacks the starch, converting it into dextrin and maltose. The ash of wheat contains principally phosphoric acid and potassium; magnesium ranks next; then lime, silica, phosphate of iron, soda, chlorine, and sulphuric and carbonic acids. CHAPTER X. BREAD MAKING AND BAKING. The ordinary method of bread-making in London is as follows: The first process, when the bread is made with thick yeast, being to prepare a mixture of potatoes, yeast, and flour, by which the process of fermentation is to be produced in the dough. Mr. George W. Austin, in his pamphlet on _Bread, Baking, and Bakers_,’ says about the ferment: ‘For each sack of flour (280 lbs.) about 8 lbs. or 10 lbs. of dry, mealy potatoes are taken, well boiled and mashed and washed through a strainer to take away the skin; to this is added 12 or 14 quarts of water, at a temperature varying from 80 deg. to 90 deg., and a quart of thick brewers’ yeast, or 1 lb. of compressed yeast—which is equal. Having well dissolved the yeast, and added 2 lbs. of flour, the mass is allowed to stand some three or four hours, until the head falls in through the escape of gas.’ The next process is the preparation of the sponge. The trough and flour being ready, the ferment is taken, and, with the addition of 28 quarts of clear water, at a temperature of 80 deg. to 90 deg., is passed into the trough through a sieve or strainer, and the mass, being kept well together, is made up into a nice dry sponge. It is allowed to remain thus and ferment for another five or six hours, when it will have risen and formed a head, which is allowed to break. As soon as this head is broken it commences to rise again, and as soon as it has broken the second time the remainder of the flour is added, and the dough made as follows: Two and a half pounds of salt dissolved in 28 quarts of clear water, at a temperature of 80 deg., and mixed well into what is termed ‘the sponge,’ with the remainder of the flour, the whole being broken up and well and thoroughly mixed and kneaded until the dough is uniform in material and consistency. It is then left to rise for another hour or more, when the dough is weighed out in pieces of the requisite size and speedily manipulated into the required shape. As the loaves are moulded they are placed on trays, covered with a light cloth (to prevent the dry and colder air forming a dry crust on the surface), and left to dry sufficiently before being placed in the oven. Before this is done the loaves are slightly brushed over with a small quantity of milk and water to improve the appearance of the outside of the loaf when it comes from the oven.