VINOUS FERMENTATION. 43 



incapable of a6ling upon fugar, yielding no ammonia on diilil- 

 lation, and leaving a coal, that burns with fcarcely any refi- 

 duum; in (hort, exhibiting characters that diftinguifli it from 

 all other fubftances, and induce me to confider it as a peculiar 

 matter. 



It appears then, that ferment takes oxigen from fugar, not The hidrogen 

 only by means of part of its carbon, but alfo by means of part "^ t^^ ferment 

 of its hidrogen ; for the quantity of carbon given out by fer- 1^3 oxigen in 

 ment is too fmall, to be the fole germe of fermentation. The producing fer- 

 azot difappears, and enters perhaps into the compofition of the 

 alcohol; the other principles of the ferment form acetous acid, 

 ^ and a peculiar infoluble white matter, which is precipitated. 

 The acetous acid remains in folulion in the liquor left after dil- 

 tillation, with an extradive matter, proceeding no doubt from 

 the fugar, and foreign to it. 



It is not probable, that the elements of the fugar, in their The dementi 

 readion upon each o^her when the equilibrium between them of the fugar 

 is difturbed, form water: there is very little hidrogen in fugar, ^°j"° "'^"^ 

 and a great deal in alcohol; and befides, on adding together 

 the quantity of carbonic acid, of alcohol, of extra6live mat- 

 ter, and of reliduum, we have a deficiericy of one eleventh ^ lofs of one 

 only of the matter by which they were produced. This lofs eleventh owing 

 muft be attributed to the water the fugar contains, and is' by e'd Tn the*^ fuea "' 

 no means owing to alcohoPs being carried off by the carbonic No alcohol car- 

 acid. Of this I have been convinced my felf by receiving "^'^j.'lj^j^ ^^.^j^^ 

 more than thirty litres of this gas in cauflic potafli; andbydif- 

 tillation and redlification I obtained only a few grammes of 

 fluid, which had fo little tafte of fpirit, that it was not to be 

 diftinguilhed."^' 



This 



on the contrary there be much fugar and little ferment, the fedlment This depends on 

 formed will contain but little yeaft, and perhaps even none; and ^he proportion of 

 then it will confift entirely of the white fubftance here mentioned, the fugar '^'' '° 

 while the fupernatant wine will or may be of a faccharine quality. 

 Thus fhould yeaft even be a produ6l of fermentation, it would aft 

 an important part in this phenomenon; and if it do not give rife to 

 it in the firft place, which is not certain even in this cafe, at leaft 

 it continues to give rife to it. This was the reafon why I faid be- 

 fore, that in all cafes nature afforded us numerous applications of 

 the theory I laid down. 



* Cit. Seguin has laid before the Inftitute a very different theory Seguin's theory 

 of fermentation. He thinks, that in this procefs water is decom- of fermentation, 



pofed. 



