Experiments and observations relating to acetons acid, fixable air, dense inflammable air, oils, and fuel ; the matter of fire and light, metallic reduction, combustion, fermentation, putrefaction, respiration and other subjects of chemical philosophy / By Bryan Higgins, M. D.

  • Higgins, Bry. (Bryan), 1737?-1820.
Date:
1786
Catalogue details

Licence: Public Domain Mark

Credit: Experiments and observations relating to acetons acid, fixable air, dense inflammable air, oils, and fuel ; the matter of fire and light, metallic reduction, combustion, fermentation, putrefaction, respiration and other subjects of chemical philosophy / By Bryan Higgins, M. D. Source: Wellcome Collection.

    364/376 (page 346)
    And now the reafon is obvious, why vine^ gar may bb made of wine, but no wine.of vinegar, by ordinary fermentation ; and the anfwer is eafy, in regard to every queftion that has ever been agitated on the fubjedt of fermentation, unlefs we except that concerning the agency of yeafl and leaven. 1 Yeaft is not always neceffary to the vi- nous fermentation ; .but wh.en it is ufed to infure it, under unfavourable circurnftances of cold air, imperfedl folution of farina- ceous matter, orvicidityof the fermentable liquor, it feems to ferve only, like the par- tial ignition formerly defcribed, to give in fome part of the mafs, a certain prepon- derance of the forces which tend to the new combinations, over thofc of the che- mical attradlions, gravitation, aggregation, and inertia, which confpire to maintain the fermentable liquor unaltered.-;■ The matter which gives this preponderance, might eafily be afeertained’by an accurate analylis of yeaft. It feems to be acetous acid, already formed, and engaged in mag- nedan earth and oil, beyond the quantity neceftary