376 



BACTERIOLOGICAL CHEMISTRY 



" firmly bound " lipoids can be precipitated from ether 

 solution by alcohol or acetone. By filtration through a 

 Chamberland candle the extracts from human and avian 

 tubercle bacilli can be separated into filterable and 

 unfilterable fractions. The extract from the leprosy 

 bacillus is all filterable. Their composition is shown in 

 Table 25 :— 



Table 25 

 ( After B. J. Anderson) 



The unfilterable fractions contain twice as much 

 polysaccharide as the filterable fractions. The poly- 

 saccharides are similar to that of the human purified 

 wax and give mannose, c?-arabinose and galactose on 

 hydrolysis (that from the leprosy bacillus contains no 

 mannose and only 1 per cent, of galactose, being almost 

 entirely composed of c?-arabinose, with a small amount 

 of an unidentified pentose). The polysaccharides all give 

 about 50 per cent, of reducing sugar on hydrolysis. 

 The non-reducing portion has not yet been identified. 

 They give precipitin reactions with the homologous 

 antisera. 



Tlie lower fatty acid fraction from the filterable 

 fraction contained tuberculostearic acid but no phthioic 

 acid. The hydroxy-acid from both human tubercle 



