gedient will be disengaged at the very commencement of fermentation: hence we obtain wine, brandy, cider, beer, &c. from grapes, apples, pears, and other fruit, from every species of corn, as well as from saccharine and mealy roots. Their productions, however, so far differ from each other, that wine contains a greater proportion of spirituous, and less of mucilaginous particles, than beer; and that distilled spirits are deprived of all earthy and viscous ingredients. But, as all fermentable bodies, beside the inflammable spirit, possess a portion of acid and saline particles, which are not disengaged during the first, or vinous stage of fermentation, another separation of constituent parts takes place, immediately after the former is effected, without any farther discharge of air-bubbles, or intestine commotion of the fluid; though a volatile elastic vapour is observed to escape: thus, the spirituous parts, unless they have been previously drawn off by distillation, are communicated to the atmosphere, and this stage is termed the acetous fermentation; because its productions are the different sorts of vinegar obtained from wine, beer, fruit, corn, &c.—Although, in most of the fermentable substances, these two stages naturally succeed each other; yet, by improper treatment, the acetous fermentation sometimes appears before the vinous can possibly commence, especially where the process is mismanaged by too great a heat; or, in those bodies which possess little or no inflammable matter in their elements. On the contrary, such vegetables as originally contain a sufficient proportion of aërial and fiery constituents, will easily ferment, by the simple means of warmth and water. But, if those elementary ingredients be in a manner deprived of their activity, by too many crude and viscid particles being combined with them, it will then be necessary to make certain additions, partly natural, and partly artificial, in order to dispose them more readily to ferment. These means, or additions, are such as have either already undergone fermentation; or are easily disposed to ferment: of the former kind are yeast and leaven; of the latter, honey, sugar, especially in a state of molasses, and other sweet substances, which, however, but slowly promote fermentation; nay, if they be previously diluted or dissolved in too hot water, and in that state added to the fermentable materials, they will entirely check that process. There are, besides, other means of promoting it; for instance, the dried leaves of the vine in a state of powder; cream of tartar, especially after it has been repeatedly moistened with strong vinegar, and afterwards dried; the crumb of bread prepared in a similar manner, and reduced to powder, &c.
If fluidity, warmth, and fresh air, forward the fermentative process, the contrary of these, namely, dryness, cold, and exclusion of air, inevitably tend to prevent it.—There are, however, cases in which it may become necessary to impede its progress; and we may then safely resort to the means above alluded to.—But a certain degree of heat, such as we have before stated, appears to be indispensably necessary to conduct that process with success: an undue continuance, or the least increase of heat, proves detrimental, while an
