FERMENTATION OF THE FATTY ACIDS. 605 



results ; or, in the third place, a decomposition occurs, in which 

 acetic acid is chiefly formed (from 100 grammes of tartrate of 

 lime Fitz obtained 45 grammes of acetate of lime), and, in 

 addition, a3thylic alcohol, butyric acid, and succinic acid. 



According to Koenig* there is obtained from a solution of 

 tartrate of ammonia together with nutrient salts, on the 

 addition of a drop of putrid fluid, a slight development of gas 

 (carbonic acid and hydrogen), a large quantity of succinic 

 acid, and a little formic acid and acetic acid. From tartrate 

 of lime infected with the same material (which, however, 

 forms an unknown mixture of bacteria) there results no suc- 

 cinic acid, but carbonic acid, acetic acid, formic acid, pro- 

 pionic acid, and a little butyric acid. 



According to Fitz's experiments, citrate of lime furnishes 

 large quantities of acetic acid, under the influence of small, 

 thin bacilli (from hay-water), while as bye-products we have 

 aethylic alcohol and succinic acid. Mucic acid also is, ac- 

 cording to Schiitzenberger, readily split up into acetic acid, 

 carbonic acid, and hydrogen. 



Finally, we may mention here the fermentation of quinate 

 of lime, which has been observed by Loew, from which, when 

 air is present, there results protocatechic acid ; but when 

 oxygen is absent, acetic acid and propionic acid. 



Although the progress which has been made during Incomplete- 



,, , , f , ,. ,, , f f fa ness of these 



the last few years, as regards the method of performing experiments 

 these experiments on fermentation, in that attention ^ fermenta- 

 has been paid to the purity of the organisms sown, is 

 very marked, we must accept with a certain reserve 

 all the decompositions which have been referred to in 

 the foregoing paragraphs, because in almost all the 

 experiments the purity of the cultivations is not abso- 

 lutely free from question. In order to obtain a really 

 trustworthy result, it is evidently not only necessary 

 to cultivate the fermentative agents pure, and to sterilise 

 the fermentescible substratum carefully, but it is also 

 well, after tbe termination of the fermentation, to examine 

 the remaining fluid with the aid of tbe recent bacteriologi- 

 cal methods in order to ascertain that no other bacteria 

 than those tbat were sown are present, and have taken part 

 in tbe decomposition observed. It is absolutely necessary 

 to require these precautions on account of tbe danger, 

 never completely avoidable, of tbe accidental entrance 



* Koenig, Chem. Ber., vol. 14. 



