536 Royal Society. 



5 of sugar, or other vegetable matter, and 61 of oxygen from the at- 

 mosphere, combine to form 100 parts of acetic acid, and about 24 of 

 water; leaving an insoluble substance at liberty to form other com- 

 binations : and thus includes in his account of this process the decom- 

 position of vegetable matter, which is overlooked in the generally re- 

 ceived theory. 



During the putrefactive fermentation of vinous fermented liquors, 

 when exposed to the atmosphere, the author considers that one equi- 

 valent of carbon from the defiant gas (= G-12) unites with two of 

 oxygen from the atmosphere (= 16) to form 22-12 parts of carbonic 

 acid : while one equivalent of hydrogen from the oletianl gas (= ]•) 

 combines with one of atmospheric oxygen (=8-) to form 9 parts of 

 water ; a portion of sugar, or other vegetable matter, being also de- 

 composed ; and an insoluble substance remaining, which, on exposure 

 to the air, undergoes further decomposition, and forms products highly 

 deleterious. The author is not aware that this latter decomposition 

 has been hitherto noticed. 



Daring the putrefactive fermentation of acetic acid exposed to the 

 atmosphere, he regards one equivalent of carbon from acetic acid 

 (= 612) as combining with two of atmospheric oxygen (= 16") to 

 form 2212 parts of carbonic acid : the oxygen and hydrogen, with 

 which the carbon had formed the acetic acid, remain in the state of 

 water, as they are found by analysis in this substance : a portion of 

 vegetable matter is also decomposed ; and an insoluble substance left 

 behind. Other substances are also formed during some of the changes 

 resulting from exposure to the air. 



During the direct putrefactive fermentation of solutions of sugar, 

 or other vegetable matters, he finds, that one equivalent of its car- 

 bon (= 6'12) unites with two of atmospheric oxygen (= 16') to 

 form 22" 12 parts of carbonic acid ; leaving the water and an insoluble 

 substance to undergo changes as before mentioned. The defiant gas, 

 formed during the vinous fermentation, whether the liquor be in the 

 state of vinous fluid, weak spirit, strong spirit, or even of alcohol, or 

 ether, is subject to precisely the same decomposition, under favour- 

 able circumstances for such changes, without any action upon, or re- 

 lation to the water which may happen to be combined with it in each 

 kind of liquor. This olefiant gas cannot, either by distillation or other 

 means, be separated along with any of the water with which it is at 

 first combined, and again united with the same materials, without 

 forming a compound different from the original one : and in propor- 

 tion as water is, by any means, removed, we obtain it in a somewhat 

 different state ; and this happens without reference to a separate and 

 distinct substance which we may call alcohol, or ether. Thus neither 

 of these two ill-defined substances ought to be regarded as a separate 

 and distinct principle ; but the whole series of bodies, from the weak- 

 est fermented liquor, separated from its vegetable matter, to the most 

 highly rectified ether, consist only of different combir .tions of olefiant 

 gas, the first ])roduct of vinous fermentation, and water. 



11. " On the Chemical Changes occurring in Seeds during Ger- 

 mination." By the same. 



