The Spirituous Parts of Plants, or those which contain the Odour and Taste, are very volatile, will mix with Water, and sometimes burn in the Fire, the Oyl of the Vegetable being here greatly attenuated, broke, and subtilized; as appears by its being exhalable by the Heat of the Summer Sun, so as to form the particular Atmosphere of the Plant, and fill the Air with Particles that affect our Senses even at some Distance. Gums are such Productions of Vegetables, as will mix with Water, dissolve over the Fire, and burn away, being tough viscid Substances, and contain a large Proportion of the Oyl and Salt of the Plant. Balsams are native Oyl of Vegetables, brought to a thick Consistence, but containing a large Proportion of an acid Spirit and Salt: However, they differ greatly from the Oyls they afford. Lastly, Resins are such Productions of Vegetables, as being hard and dry, prove brittle in the Cold, soluble by Heat, inflammable and misceable with Oyl, but not with Water. It would be endless to give an Account of the particular Qualities of the proper Juices of Plants; since these differ in different Plants, and many Times in different Parts of the same Plant. There is a much greater Variety in Vegetable than in Animal Nature; and a much greater Difference in the Juices of one than of the other; for the Number of different Plants known and used very much exceeds the Number of different Animals known and used; and particular Plants have greater Variety of Juices than particular Animals; whose Juices (if I may so speak) are more homogenial than those of Plants. This will appear more evidently by comparing what hath been here said, with the Consideration of Animal Substances with Regard to Diet. I have hitherto considered Vegetables in their natural State, but before we can apply what hath been laid down to Animal Diet, we must consider some Changes many of them undergo, before they are used. The Chief of these happens by Fermentation, the Effects of which upon Vegetables deserve to be considered; since Bread, Wine, and Malt Liquors, so great a Part of our common Food, are prepared from Vegetables that have gone thro’ this Operation, or are mixed with Ferments in their Preparation.