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 cause of this sublime operation is owing, but it is to the very variable proportions between these different constituent principles, that the chief differences, presented by fermentation, are to be referred.

It appears proved, by the comparison of the nature of all substances which undergo the vinous fermentation, that only such as contain the saccharine principle, are susceptible of it; and it is beyond a doubt, that it is chiefly at the expense of this principle that alcohol is formed.

To give more precision to these ideas, it may be observed, that, at the present day, three sorts of sugar are distinguished, which, though very different in appearance, possess, in common, the property of yielding alcohol by fermentation.

The first species of sugar, is that extracted from the sugar cane, the red beet, the maple, and the chesnut, which is capable of being crystallized, and in these different plants is exactly of the same nature.

The second species of sugar, is afforded by the grape, by honey. &c. This has been reduced, by art, to the state of a fine powder, soluble in water, but all attempts to obtain it crystallized, have been unsuccessful. It is inodorous, agreeable to the taste, and its saccharine virtue is weaker than that of the first species, requiring three or four times