108 CHEMISTRY OF BAVTEIUA AM) Til El I! I'RODUCTS 



are much more modified by tlieir enviroiinieiit than are higher or- 

 ganisms. They usually contain between 80 and 90 per cent, of water. 

 Grown on a salt-rich medium they yield much ash; grown on a pep- 

 tone-rich medium they contain nnich protein ; grown on a fat-rich 

 medium they contain much material solubU^ in ether. Cholera vibrios 

 grown on a bouillon medium contained ()i).25 per cent, of protein, and 

 25.87 per cent, of ash, whereas the same organism grown on Uschin- 

 sky's medium, which contains no proteins but only various simple 

 chemical compounds, contained but 35.75 ))er cent, of protein and 

 13.7 per cent, of ash (Cramer). Even in the same medium two 

 different strains of the same organism may show e(iually great dif- 

 ferences: Two strains of cholera vibrios grown on the same medium 

 showed respectively 65.63 per cent, and 34.37 per cent, of protein. 

 It is evident, therefore, that quantitative analyses of bacteria show 

 nothing as to their nature, and on account of the extreme limits of 

 their variation ai'c practically valueless. The specific gravity of bac- 

 teria, generally between 1.12 and 1.345, also varies with media and 

 age.^ In an electric field they move towards the anode."' 



Qualitatively the variations are not so great — all bacteria contain 

 proteins, lipoid substances, and salts, of which phosphates are most 

 prominent in the ash. The character of the proteins and fats of 

 bacteria grown on peptone bouillon is (juite the same as when they 

 are grown on protein-free media.'"'^' The older analyses of bacterial 

 constituents are of little value. Recent studies prove that the chief 

 constituent of the cell .contents is a true nucleoprotein (Iwanoff '^) con- 

 taining some sulphur and iron ; probably many of the "pyogenetic pro- 

 teins," "bacterial toxalbumins, " "bacterial caseins" of earlier investi- 

 gators are true nucleoproteins.^^ The stainable substance of anthrax 

 bacilli behaves as if it were a chromatin, while the spores resemble linin 

 fRuzicka'). The predominance of nuclein compounds is shown by 

 Ruppel's summary of the composition of dried tubercle bacilli, 

 namely, in per cent., tuberculonucleic acid, 8.5 ; nucleo-protamine, 24.5 ; 

 nucleo-protein, 26.5 ; fatty matter, 26.5 ; inorganic, 9.2 ; insoluble 

 "proteinoid" residue, 8.3. In a water bacillus Nishimura found 

 xanthine, guanine, and adenine, indicating the presence of nucleo- 

 protein; others have found that bacterial nucleoprotcins s])lit off 

 pentoses, as do the nucleoprotcins of higher cells. If it is true tliat 

 bacterial luiclco-proteins contain pentos(> it ranks tluMU with tlie plant 



4Rtip('ll, Cent. f. I?akt., 1007 (4.3), 4S7. 



•'"' Jinx ton, Zcit. ]»liysil<al. C'licni., liKU; (57), 47; concprninfj the rlcctriral cnn- 

 ductirH)/ of liactcria sec 'Iliornton. Troc. T\oval Soc, London, Sec. B., 1013 (85), 

 3.31. 



•laTannira. Zcil. iilivsiol. Clicni.. lOl.S (SS), lon. 



Hofnieistcr's Heitr., 1002 (1), 524 ; liililio,-ra|.liy by Lus(i<:-. Kollc and Wassor- 

 mann's Handliucli, 1013 (ii), 1302. 



«" The ])nri1v of inanv of llic jJi-cparalions \Mirk(<l with as bacterial niulcopro- 

 teins, is vcrv donlitful. " (See W.-lis, Zeit. Inununiliit .. lOl.'i (19), 500.) 



7 Arch. KnlwicklniiKsink.. I'KX; (21). 30(i. 



