62 PROTEIN POISONS 



glyceride of a volatile fatty acid to which cultures of this 

 bacillus owe their characteristic odor, also a very small 

 amount of an acid (probably lauric) melting at 42 to 43, 

 and an unusually high melting acid, one apparently with a 

 larger carbon content than any before noted in plants. 

 Ruppel 1 obtained three extracts from the tubercle bacillus 

 by using successively cold alcohol, hot alcohol, and ether. 

 The first contains free fatty acids and a fat melting between 

 60 and 65, easily saponified and decomposed into a free 

 acid and a higher alcohol. The second contained a waxy 

 mass, saponified with difficulty, and which seemed to be 

 the ester of a fatty acid and a high alcohol. The third 

 melted at 65 to 67, and had an odor resembling that of 

 beeswax. Aronson 2 obtained from tubercle bacilli, by 

 means of a mixture of five parts of ether and one of abso- 

 lute alcohol, a yellowish-brown tenacious mass, constituting 

 from 20 to 25 per cent, of the dried bacilhis. From the 

 growth of several hundred liters of culture 70 grams were 

 secured. This contained 17 per cent, of free fatty acids. 

 The remainder was wax, not acid and glycerin, but esters 

 of acid and alcohol insoluble in water. Most of this wax is 

 not in the cells, but lies around and between them. Levene 3 

 found almost 30 per cent, of fat or wax in tubercle bacilli. 

 Kresslig 4 extracted tubercle bacilli successively with ether, 

 chloroform, benzol, and alcohol, and obtained 38.95 per 

 cent, of fatty and waxy substances. Repeated extraction 

 with chloroform gave a dark brown mass of the consistency 

 and color of beeswax and melting at 46. He found 14.38 

 per cent, of free fatty acid, 77.25 per cent, of neutral fat 

 and esters of fatty acids, and some volatile fatty acid, 

 probably butyric. He decided that the fat of the tubercle 

 bacillus is quite different from that obtained from any 

 other source. 



Reducing Action of Bacteria. Although the general 

 subject of the reducing action of bacteria scarcely falls 



1 Loc. cit. 2 Berl. klin. Woch., 1896, xxxv, 484. 



3 Loc. cit. 4 Centralbl. f. Bakteriol., 1901, xxx, 897. 



