CHEMICAL COMPOSITIOX OF BACTERIA 111 



acids, and there is some laiiric acid in the form of a soap. Cholesterol 

 could not be found in tubercle, diphtheria and other bacteria examined 

 by Tamura, although there probably are lipochroines giving the cul- 

 tures their color. There is still, however, much disagreement as to 

 whether the acid fastness of tubercle bacilli depends upon waxes, 

 alcohols, fatty acids, or lipoid-protein compounds.^" It must be ad- 

 mitted that a high content of fatty materials is regularly present in 

 acid-fast bacilli; thus, in an acid-fast bacillus isolated from leprous 

 lesions, 34.7 per cent, of fats, fatty acids and cholesterol, and 1.7 per 

 cent, of lecithin were found by Gurd and Denis.-" 



Tamura-"'' states that the phosphatids of B. tuberculosis and a 

 saphrophyte examined by him were not lecithin but a diaminophos- 

 phatid, although diphtheria bacilli seemed to contain lecithin.-"*^ He 

 found in both a high molecular alcohol, "mykol," to which he ascribes 

 acid- and Gram-fastness. In a Gram-negative bacillus -°*^ he found 

 lecithin, but no cholesterol or mykol. By growing tubercle bacilli 

 on suitable media they can be made to lose their acid-fast property, 

 although still Gram-positive (Wherry ^'"^). The observation of ]\Iiss 

 Sherman,-^ that tubercle bacilli are almost absolutely impenneable 

 to fat-soluble dyes which stain their isolated fats well, and her cor- 

 roboration of Benians' demonstration that acid-fastness depends on 

 the integrity of the bacillary envelope, make the role of the fatty sub- 

 stances uncertain. Their high content in unsaturated fatty acids 

 gives them a high antitryptic power which may be concerned in the 

 defense of the bacteria, and also in the persistence of caseous ma- 

 terial in tubercles (Jobling and Petersen).-^-'' 



By staining with Sudan III, Sata -- demonstrated fats, not only in 

 the acid-fast bacilli, but also in anthrax. Staphylococcus aureus, B. 

 mucosus, and actinomyces; but not in diphtheria, pseudo-diphtheria, 

 plague, cholera, and chicken cholera bacilli, or in members of the 

 colon group. -^ Only a few bacteria form fat on agar free from 

 glycerine, but potato is a favorable medium. Ritchie -* obtained 

 positive fat staining in B. diphtheria' and anthracis, but not in 

 S. pyogenes aureus or M. tetragenus, although these last forms contain 



19 See Camus and Pagniez, Presse MM., 1007 (15), 65; Devkc, ^liinfh. mod. 

 Woch., 1910 (57), 633. 



20 .Jour. Exper. :\[ed., 1911 (14), 606. 

 20aZeit. phvsiol. Chem.. 1913 (87), 85. 

 20hlhid., 1914 (89), 289. 



20c Ihid., 1914 (90), 286. 



20d Jour. Infect. Dis., 1913 (13), 144. 



21 Jour. Infect. Dis., 1913 (12), 249. 

 2ia.Joiir. Exp. Med., 1914 (19), 239. 



22 Cent. f. allg. Path.. 1900 (11). 97. 



23 Auclair (Arch. Med. Exper.. 1903 (15), 725) contends that the ether and 

 chloroform extracts of many patho>renic bacteria contain important toxic sub- 

 stances. Holmes (CJuy's TIosp. Reports, 1905 (59), 155) states that injection 

 of fattv acids from tuljercle bacilli into rabbits causes a lymphocytosis. 



24 Jour. Pathol, and Bact., 1905 (10), 334. 



