The oven is, for the purpose of baking bread, brought up to a heat of 400 deg. Fahr., and the bread, although seemingly baked by dry heat, is in reality boiled in the steam of the water which the bread contains.[14] Salt is added to make the bread more palatable; but it has also another effect. With inferior flour dextrin is formed inside the loaf to some extent as well as on the outside, consequently bread made from inferior flour rises badly and is darker in colour. This inferior flour is made sometimes from wheat that has been damp, the dampness causing the soluble albumenoids which the grain contains to act on the insoluble gluten, decomposing it into soluble bodies, and producing dextrin by their action on the starch in the grain. The further decomposition of these albumenoids is checked by the action of the salt during the fermentation of the bread. And now it will be well to say something about the leaven of bread. We have already seen the modern method of making a ferment with flour, potatoes, and brewer’s yeast; but there are other substances which do not cause fermentation, and yet lighten the bread, such as the different baking powders, and the American _sal eratus_, a mixture of bi-carbonate of soda and salt. Carbonate of ammonia, which entirely evaporates in baking, is used in confectionery to raise the paste by the bubbles it forms in its volatilisation. The unfermented breads, such as those made by the late Dr. Dauglish’s patent (of which more anon), are rendered light upon the same principle, the usual method being to mix soda with the flour, and hydrochloric acid with the water, in the proportions in which they unite to form chloride of sodium, or common salt. The effervescence, like that produced in mixing seidlitz powders, converts the paste into a porous sponge, which, however, requires to be very quickly placed in the oven. The salt formed by the mixture replaces that ordinarily added to the dough in making bread; but this method is seldom used by practical bakers. Whatever, therefore, be the method by which bread is made light, the object to be attained is to pervade the dough with numerous cavities, which keep the particles of flour asunder, instead of forming a compact and unyielding mass.