In examining vegetable Substances as Food, we must consider them as eaten Raw, as prepared by the Arts of Cookery, and as subjected to Fermentation. In the first Case they are sometimes the Food of Men, always of Animals that we feed upon; in the others the Food of Men alone. Raw Vegetables that become Parts of Animals, are bruised, ground, and comminuted by the proper animal Organs, and mixed with animal Juices in their Passage. By this Means their Juices are expressed; such of them as are capable of mixing with Water naturally, or by the intermediate Assistance of the Bile, are formed into one common fluid Mass or Chyle, which constitutes the first Nourishment of Animals; whence the Blood, Serum, Lymph, and other animal Juices are formed. From what was said before, this appears to be the Water, impregnated with the essential Salt, the Spirit, some Portion of its essential Oyls, mixed with the Water by Means of the Salt and the Bile; these by the vital Powers are formed into a white Liquor, which is the Chyle, not unfitly represented in the common making of Emulsions from oily Seeds. The Chyle still retains its vegetable Nature, and somewhat specifick to the Vegetable it came from; but when it hath been circulated several Times thro’ the Body, and thoroughly mixed with the Juices thereof, it acquires animal Properties; vegetable and animal Juices are pretty near of the same specifick Gravity, and consequently fit to repair each other; the different Impulses of Heat and Motion, with due Mixture, create the Difference; though this will always hold true, that an animal Body constantly repaired from vegetable Juices, cannot have so strong a tendency to a putrescent alkaline State, as a Body constantly repaired from animal Juices, already disposed to that State. The common Effects of the Art of Cookery upon Vegetables, will be understood by what happens in the Decoction of Plants. In boiling any Plant, its most sublime fluid Part flies off, and indeed it is incapable of bearing a greater Heat than that of the Summer Sun, the Salts of the Plant are dissolved in the Water, and its thicker and grosser Oyl rises to the Top, like a fat Scum; so long as the Plant retains any Taste or Odour, change the Water as often as you please, there will constantly arise a fat, odorous, viscous, inflammable and frothy Matter, which can be no other than the Oyl of the Plant loosened from the Salts. In Proportion then, as the Salts are dissolved in the boiling Water, the Oyl attenuated, as it must be before it can be so far specifically lighter as to arise to the Top, we are to judge how far the Art of Cookery is serviceable in the Preparation of vegetable Diet.