= of the 



^tions 



cannot 



from othet 

 his catei 



?es which are 

 ^ns, there are 

 iy associated 



,y, only to be 



organisms or 



tiie fact that 



ionally when 



dicated. 



e pre 



tioo 



h predica 

 and pepsins 



Tiilar change 

 acid ; an^ 

 breakin 



c 



o-.yp 



ute 

 ■e. 



[on 



of ac^* 



in 



in 



fl 



.n 



dtbe» 



i# 



tive 



c 





yy/fi' BEGINNINGS OF LIFE. 



409 



according to M. Pasteur^ is brought about by a living 

 organism, the vinegar-plant {Mycoderma acett) ; but, as 



Liebigj acetic acid 



may 



we are reminded by Baron 

 be similarly derived from alcohol through the agency 

 of finely-divided platinum, as was first pointed out 

 by Dobereiner. The finely-divided platinum has the 

 power— and many organic substances have a similar 



property — of 



absorbing 



oxygen from the air, and 



bringing it into a condition in which it can unite with 

 other substances with which it would not otherwise enter 

 into combination at low temperatures. So that, when 

 alcohol is subjected to the influence of finely-divided 

 platinum, it is first converted into aldehyde, owin 

 to the oxidation of its hydrogen, whilst aldehyde, 

 by a further oxidation, is converted into acetic acid. 

 And, according to Liebig, the method introduced by 

 Schutzenbach in 1823, for the manufacture of vinegar, 



■ 



is based upon this theory. He says ^ :— ^ In this 

 operation wood shavings or fragments of charcoal are 

 used for determining the oxidation. At one of the 

 largest vinegar factories in Germany, the dilute alcohol 

 receives no admixture during the whole operation ^ 

 besides air, and wood shavings, or charcoal, there is no 

 other substance concerned, and the fresh supply of 

 dilute alcohol is only mixed with a little of the 



unfinished vinegar from a 



previous operation 



The 



proprietor of these works, Hy. Riemerschmied, sent me 



' On Acetic Fermentation, translated in ' Pharmaceutical Journal/ 

 ■A^ug- i3> 1870? P- 124. 



\ 



