34? VINOUS FERMENTATION. 



he did, he obferved that firidnefs of dedudion and accuracy 



of operation, which are liis charaderiftics, and which may be 



confidered as tlie fourcc of the fplendid difcoveries, that will 



But he left it for ever illufirate his name. Still, notwithflanding the ex- 



imper c . cellence of what he did, he was far from leaving nothing more 



to be done. Though he flied great light on this part of fcience,'* 



the obfcurity with which it was enveloped was fo great, that 



it is flill feen only through a raift. This is a truth that did not 



efcape liimfelf ; he was well aware that he had only laid open 



tile path to the goal, which no doubt he would ha;i'e reached, 



no doubt he would have completed the career he had begun 



with fuch fuccefs, had not death, jealous of his fortune and 



glory, robbed fcience of his labours. 



In fermentation All we know of fermentation in fa6l is confined to this, that 



fugar IS convert- ^^j^^ faccharinc matter is converted into alcohol and carbonic 



cd into alcohol r • ^• r i n 



andcaibonic acid by means of an nitermediate fubuance. But what is the 

 acid, by means of j^j^^m-^ of this fubftance ? and how does it a6l on the fugar? 

 fubftmce. But Thefe two grand queftions form the fubje(5l of the prefent 

 what is this? memoir; queftions that have been often attempted, without 

 a£l? °^ °^ ' ever having been folved. Some have thought, that the ferment- 

 IraagineJ to be ing principle refided in the extradive matter. Others would have 

 ^traftive mat- jj_ ^^ j^^ -^^ ^j^^ mucilage, becaufe this more frequently accom- 

 mucilage, ' panics the extra<5live matter. Some, again deceived by the 

 ^^'^.^'i' . „ . prefence of tartar in wine, have imagined they found in this 



which laft IS not ' ,. t -r • n i r <• ■ 1 ri i 



found in all fer- the true torment ; but if, mltead or confinmg themielves to the 

 menting liquors, fermentation of the muft of grapes, they had turned their at- 

 tention to that of other juices, in which analyfis cannot difcover 

 the exiftence of this fait, they certainly would not have fallen 

 into this error. Others, laftly, inconfiderately adopting all thefe 

 or a mixture of opinions, have afierted, that a mixture of thefe different matters 

 * ' ^^* prefide as it were over fermentation, effe6ling the decom- 



pofftion of the fugar, and its converfion into alcohol *. 



Of thefe hypothecs fome are evidently falfe; others are 

 feducing, and acquire; from fpecious reafoning fome degree of 

 probability. But before we admit them, we mufl confult ex- 



* Mr. Thenard here gives a long note, to prove he had not feen 

 the prize elTays written in 1787 and 1788 by Fabroni, from whom 

 fome pel fons at Paris accufed him of having borrowed, and to fhow, 

 that Fabroni and he differ eflentialJy in this theory,* but it is here 

 omitted as irrelevant.. T, 



perience ; 



