the meal of wheat-corn, finely ground and sifted. See Meal.

The grain itself is not only subject to be eaten by insects in that state; but, when ground into flour, it gives birth to another race of destroyers, who eat it unmercifully, and increase so fast in it, that it is not long before they wholly destroy the substance. The finest flour is most liable to breed these, especially when stale or ill prepared. In this case, if it be examined in a good light, it will be observed to be in continual motion, and on a nicer inspection there will be found in it a great number of little animals of the colour of the flour, and very nimble. If a little of this flour is laid on the plate of the double microscope, the insects are very distinctly seen in great numbers, very brisk and lively, continually crawling over one another's backs, and playing a thousand antic tricks together; whether in diversion or in search of food, is not easy to be determined. These animals are of an oblong and slender form; their heads are furnished with a kind of trunk or hollow tube, by means of which they take in their food, and their body is composed of several rings. They do vast mischief among magazines of flour laid up for armies and other public uses. When they have once taken possession of a parcel of this valuable commodity, it is impossible to drive them out; and they increase so fast, that the only method of preventing the total loss of the parcel is to make it up into bread as soon as can be done. The way to prevent their breeding in the flour is to preserve it from damp: nothing gets more injury by being put up damp than flour; and yet nothing is more frequently put up so. It should be always carefully and thoroughly dried before it is put up, and the barrels also dried into which it is to be put; then, if they are placed in a room tolerably warm and dry, they will keep it well. Too dry a place never does flour any hurt, though one too moist almost always spoils it.

Flour, when carefully analyzed, is found to be composed of three very different substances. The first and most abundant is pure starch, or white fecule, insoluble in cold, but soluble in hot water, and of the nature of mucous substances; which, when dissolved, form water glues. The second is the gluten, most of whose properties have been described under the article Bread. The third is of a mild nature, perfectly soluble in cold water, of the nature of saccharine extractive mucous matters. It is susceptible of the spirituous fermentation, and is found but in small quantity in the flour of wheat. See Bread, Gluten, Starch, and Sugar, Chemistry Index.