[40] Of a Specific Gravity. 825.
[41] Philosophical Trans. 1811, p. 345; 1813, p. 87; Journal of Science and the Arts, No. viii. p. 290.
[42] Macculloch on Wine. This is by far the best treatise published in this country on the Manufacture of Home-made Wines.
Adulteration of Bread.
This is one of the sophistications of the articles of food most commonly practised in this metropolis, where the goodness of bread is estimated entirely by its whiteness. It is therefore usual to add a certain quantity of alum to the dough; this improves the look of the bread very much, and renders it whiter and firmer. Good, white, and porous bread, may certainly be manufactured from good wheaten flour alone; but to produce the degree of whiteness rendered indispensable by the caprice of the consumers in London, it is necessary (unless the very best flour is employed,) that the dough should be bleached; and no substance has hitherto been found to answer this purpose better than alum.
Without this salt it is impossible to make bread, from the kind of flour usually employed by the London bakers, so white, as that which is commonly sold in the metropolis.
If the alum be omitted, the bread has a slight yellowish grey hue—as may be seen in the instance of what is called home-made bread, of private families. Such bread remains longer moist than bread made with alum; yet it is not so light, and full of eyes, or porous, and it has also a different taste.