The bread used in this metropolis and in most other large towns in England, is made of wheaten flour, water, yeast, and salt. The average proportion are two pints by weight, of water, to three of flour, but the proportions vary considerably with the diversity of climate, years, season, age, and grinding of the wheat. There are some kinds of wheat flour that require precisely three-fourths of their weight of water. That flour is always the best which combines with the greatest possible quantity of water. Bakers and pastry-cooks judge of the quality of flour from the characters of the dough. The best flour forms instantly by the addition of water a very gluey elastic paste, whereas bad flour produces a dough that cannot be elongated without breaking. The flour, in this case, being seldom mixed up oftener than twice, that is, the yeast previously diluted with water, is added to a part of the flour, and well kneaded; in a short time, swells and rises in the baking trough, and is called by the bakers, _setting the sponge_. The remainder of the flour is afterwards added, with a sufficient quantity of warm water to make it into a stiff dough, and then allowed to ferment. It is of essential consequence that the whole of the yeast should be intimately mixed with the two-thirds of the quantity of the flour put into the kneading trough, in order that the fermentation of the dough may commence in every part of the mass at the same time. The dough is then covered up, and the water which is mixed with the yeast being warm, speedily extricates air in an elastic state, and as it is now by kneading, diffused through every part of the dough, every particle must become raised, and the viscidity of the mass retains it, when it is again well kneaded and made up into loaves, and put into the oven. The heat converts the water also into an elastic vapour, and the loaf swells more and more, till at last it is perfectly porous. During the baking, a still greater quantity of gazeous matter is extricated by the increased heat; and as the crust of the bread becomes formed, the air is prevented from escaping, the water is dissipated, the loaf rendered somewhat dry and solid, and between every particle of bread there is a particle of air, as appears from the spongy appearance of the bread.