THE CHEMICAL COMPOSITION OF BACTERIA. 81 



In no variety of bacteria could E. Cramer discover 

 grape sugar; some varieties (bacillus butyricus, lep- 

 tothrix forms) contain starch-like masses which are 

 stained blue by iodine. True cellulose was discovered 

 by Drey fuss in bacillus subtilis and in an organism 

 closely related to bacterium coli, and the bacillus tuber- 

 culosis also forms cellulose in the animal body. But 

 no cellulose could be obtained from cultures of bacil- 

 lus tuberculosis and a "capsule bacillus from water," 

 closely related to bacillus pneumonise Friedlander, 

 while they contained a large amount of a gelatinous 

 carbohydrate (C 6 H 10 O 5 ), which is closely allied to 

 hemicellulose (concerning the literature vide Nishi- 

 mura: A. H., XVIII., 318 and XXL, 52). The mu- 

 cus of leuconostoc mesenterioides was shown by 

 Scheibler (Chem. Gentralbl, XI., 181) to be a carbo- 

 hydrate, C (i H 10 O 5 dextro-rotatorj^. Kramer obtained 

 a similar substance from the membranes of bacillus 

 viscosus sacchari. Nuclein has not been extracted, 

 but among the nuclein bases xanthin, guaiiin, and 

 adenin have been found in considerable amounts. 

 One group of bacteria deposits sulphur granules, 

 which are derived from sulphuretted hydrogen (beg- 

 giatoa, thiothrix) ; another variety, which is classed 

 among bacteria by many authors, secretes ferric oxide 

 into its membrane from ferruginous waters (cladothrix, 

 crenothrix) . 



The methodical investigations of E. Cramer have 

 shed some light upon the quantitative relations, al- 

 though accurate statements have been obtained hith- 

 erto only concerning bacterium prodigiosum, bacillus 

 pneumonias, and a few related varieties, and a series 

 of forms of vibrio choleras (vide E. Cramer: A. H., 

 6 



