4^ Scietnifc NettSj Accduiils of BdtsiSt i*fc. 



tion of oxigen appejirs alfo to be ptecipitated ort the carbdh of tlie ifdn, wHch affords thd 

 carbonic acuf, and cryftallifes the ammonhc, by fatarating it as it is formed. 



Cheniifls in general, hnve believed and advanced, that alcohol is the produce of thC' 

 vlnotis fermentation. I am afliired that it is not all fo, for it doeS not exift in \Vine. I 

 think t can render this very evident, if I have a method by which I can recover an hun- 

 dredth part of alcohol, when completely mixed with ftrong wine, in which, by the fame 

 method, 1 could not before dlfcover fiie fmallefl atom, although I could obtain 20 or 25 

 of biran'dy, from a hundrey parts by diftillation. Thefe were the fimple means by which 

 it was performed : take a glafs tube of fufficlent f\te, to introduce the finger, and divide it 

 into an hundred equal parts ; take frefli wine, with which you have mixed one hundredth 

 part of alcohol, and to that put as much pot-alh in powder, as is found by a previous ex- 

 periment, to be neceffary to precipitate the refinous coloring refidue. Then ftrain the 

 wine, and pour it into the tube, and add aS much pot-afli in powder as is required to fatu- 

 rate it. The centime of alcohol, which had been mixed with the wine, will then be feen 

 to rife, and fwim diftindly on the furface of the alkalirte folution. It will be found of the 

 fame degree of ftrength, and in the fame proportion that it had been added, if the opera- 

 tion is performed with fufficient quicknefs to avoid loGng any thing by evaporation. The 

 previous feparation of the coloring matter ferves merely to render the refulc more percep- 

 tible. Now, if by this means I procure only the fame quantity of alcohol from the wine 

 that I knew it contained before, and not a drop more, it appears to me, I have a right to 

 conclude, that that which I obtain from the fame wine by diftillation, did not exift in it 

 before, but that it is the operation of diftillation which forms it; that its formation is de- 

 termined by the heat ; and laftly, that this liquid is a produfl:, and not au edu£t of the 

 diftillation of the wine. The heat neceflary to efFe£l this is not therefore very confiderable, 

 for it is formed by the heat of the fermentation, to an heat of diftillation of 14 degrees, 

 fuch as may be obtained during winter. It may be formed in bottles by the warmth of the 

 atmofphere, &c. It is for this reafon, that I have recommended new wirtc to be ufed in 

 my experiment. AU this has been printed in my Arte difare il vim, which Was publiftied 

 at Florence in 1788 ; but Italian books feldom pafs the Alps. The anatomical examination 

 of the grape precedes the chemical part in this work. The thpory of fermentation is there 

 found explained according to the ancient principles, though at that epocha I had, for a 

 confiderable time, renounced the phlogiftic theory. The effential ingredients, the aflive 

 and pafllve principles, that is to fay, of fermentation, are there deduded from experiment ; 

 and the making of artificial wine is the confirmation of them. The work is concluded, by 

 expofing the chemical means neceffary to difcover the alteration which adi^lterated winCs 

 uildergo, and a fummary of all the theories of fermentation that have been prefented, to 

 the time of its publication. You will there, perhaps, find a phenomenon which contra- 

 difts them all, and which is very remarkable. It is that the accefs of air is not effential to 

 fermentation ; for I have excited it in the vacuum of Toricelli. 



Principkj 



