The bran, or external covering of the grain of wheat, has recently also been the subject of scientific and economical investigation. It has been proved, by the researches of Johnston, confirmed by those of Miller and others, that the bran of wheat, though less readily digestible, contains more nutritive matter than the white interior of the grain. Brown, or household bread, therefore, which contains a portion of the bran, is to be preferred, both for economy and for nutritive quality, to that made of the finest flour. Upon the economy of mixing potato with wheaten flour, and of home-made bread, Mr Stephens has the following:-- "It is assumed by some people, that a mixture of potatoes amongst wheaten flour renders bread lighter and more wholesome. That it will make bread whiter, I have no doubt; but I have as little doubt that it will render it more insipid, and it is demonstrable that it makes it dearer than wheaten flour. Thus, take a bushel of 'seconds' flour, weighing 56 lbs. at 5s. 6d. A batch of bread, to consist of 21 lbs., will absorb as much water, and require as much yeast and salt, as will yield 7 loaves, of 4 lbs. each, for 2s. 4d., or 4d. per loaf. 'If, instead of 7 lbs. of the flour, the same weight of raw potatoes be substituted, with the hope of saving by the comparatively low price of the latter article, the quantity of bread that will be yielded will be _but a trifle more than would have been produced from 14 lbs. of flour only_, without the addition of the 7 lbs. of potatoes; for the starch of this root is the only nutritive part, and we have proved that but one-seventh or one-eighth of it is contained in every pound, the remainder being water and innutritive matter. Only 20 lbs. of bread, therefore, instead of 28 lbs., will be obtained; and this, though white, will be comparatively flavourless, and liable to become dry and sour in a few days; whereas, without the latter addition, bread made in private families will keep _well_ for 3 weeks, though, after a fortnight, it begins to deteriorate, especially in the autumn.' The calculation of comparative _cost_ is thus shown:-- Flour, 14 lbs., say at 1-1/4d. per lb., = 1s. 5-1/2d. Potatoes, 7 lbs., say at 5s. per sack, = 0 2 Yeast and fuel, = 0 4-1/2 ------ 2s. 0d. The yield, 20 lbs., or 5 loaves of 4 lbs. each, will be nearly 5d. each, which is dearer than the wheaten loaves at 4d. each, and the bread, besides, of inferior quality.