“Many chemists are of opinion that flour by the fermentation in the dough loses somewhat of its nutritious constituents, from a decomposition of the gluten; and it has been proposed to render the dough porous without fermentation by means of substances which when brought into contact yield carbonic acid. But on a closer investigation of the process this view appears to have little foundation. “When flour is made into dough with water, and allowed to stand at a gentle warmth, a change takes place in the gluten of the dough, similar to that which occurs after the steeping of barley in the commencement of germination in the seeds in the preparation of malt; and in consequence of this change the starch (the greater part of it in malting; in dough only a small percentage) is converted into sugar, a small portion of the gluten passes into the soluble state, in which it acquires the properties of albumen, but by this change it loses nothing whatever of its digestibility or of its nutritive value. “We cannot bring flour and water together without the formation of sugar from the starch, and it is this sugar and not the gluten of which a part enters into fermentation, and is resolved into alcohol and carbonic acid. “We know that malt is not inferior in nutritive power to barley from which it is derived, although the gluten contained in it has undergone a much more profound alteration than that of flour in the dough, and experience has taught us that in distilleries where spirits are made from potatoes, the plastic constituents of the potatoes, and of the malt which is added after having gone through the entire course of the processes of the formation and the fermentation of the sugar, have lost little or nothing of their nutritive value. It is certain, therefore, that in the making of bread there is no loss of gluten. “Only a small part of the starch of the flour is consumed in the production of sugar, and the fermentative process is not only the simplest and best but also the cheapest of all the methods which have been recommended for rendering bread porous. Besides, chemical preparations ought never, as a rule, to be recommended by chemists, for culinary purposes, since they hardly ever are found pure in ordinary commerce. For example, the commercial crude muriatic acid which it is recommended to add to the dough along with bicarbonate of soda, is always most impure, and often contains arsenic, so that the chemist never uses it without a tedious process of purification for his purposes, which are of far less importance than making bread light and porous.