482 EXPERIMENT STATION RECOED. 



1 per cent solution. In therapeutic doses, frequently repeated for long periods, 

 trypanblue and trypanred seem to have no favorable or curative influence 

 in experimental tuberculosis in guinea pigs. In a single large, nearly lethal 

 dose at the beginning of the infection they also have no favorable influence. 



" Silver trypanblue and iron trypanblue also penetrate the tubercle, but 

 have no bactericidal and no therapeutic influence. It is doubtful whether 

 the metals are carried in with the dye. Copper trypanblue is soluble, but 

 does not penetrate either the normal or the tuberculous tissues, and is prob- 

 ably changed to an insoluble form or a suspension colloid and retained at 

 the point of injection. Mercury trypanblue is insoluble, is strongly bacteri- 

 cidal in its action on the tubercle bacillus, but is too toxic for therapeutic 

 use, since the pigs died apparently from chronic mercury poisoning, rather 

 than from the tuberculous infection, the tuberculous process being generally 

 very slight. The findings with this salt, however, are suggestive, and further 

 experiments with mercury salts will be made." 



Tuberculocidal action of certain chemical disinfectants: Studies of the 

 biochemistry and chemotherapy of tuberculosis IX, Lydia M. De Witt and 

 Hope Sherman (Jour. Infect. Diseases, 15 (1914), No. 2, pp. 245-256). — Very 

 little is in the literature in reference to the power of chemical substances 

 to kill tubercle bacilli. It has generally been accepted that tubercle bacilli, 

 though nonsporogenous, are the most resistant of pathogenic organisms. 



" Phenol in 5 per cent water solution kills human tubercle bacilli in five 

 minutes, one hour, six hours, and twenty-four hours. It is nearly as efficient in 

 1 per cent solution, and shows some tuberculocidal action down to 0.1 per 

 cent solution. Formaldehyde in 1 per cent solution kills all tubercle bacilli 

 in one hour (shorter time not tested). In 0.01 i)er cent solution it kills 

 in twenty-four hours and so no disease develops in guinea pigs. Formaldehyde, 

 therefore, is somewhat more efficient than phenol. Ethyl alcohol in 25 per 

 cent solution kills all tubercle bacilli within one hour (shorter time not tried). 

 Acetone, chloroform, and ether have very little, if any, tuberculocidal influ- 

 ence. Toluene and iodin show slight influence. 



" Of the metallic salts used, mercuric chlorid shows the greatest tuber- 

 culocidal action, O.CK)l per cent killing in twenty-four hours, and 0.1 per cent 

 in one hour. Gold chlorid in 0.005 per cent solution kills in twenty-four 

 hours, while 0.025 per cent silver nitrate kills in the same time. One-tenth 

 per cent gold tricyanid and 5 per cent copper chlorid kill the organisms in 

 twenty-four hours. 



" From a comparison of the results of the experiments contained in this 

 paper with those of disinfection work on other more rapidly growing or- 

 ganisms, the Bacillus tuberculosis appears less resistant than the streptococ- 

 cus, staphylococcus, pneumococcus, or gonococcus, or than the Bacillus typhosus, 

 coli, or anthracis spores, to phenol, formaldehyde, mecuric chlorid, silver ni- 

 trate and gold chlorid, but more resistant than these other organisms to alcohol, 

 chloroform, ether, acetone, toluene, and Lugol's solution. The fat content of 

 the tubercle bacillus does not determine its resistance to disinfectants. Our 

 experiments seem to show that if the comparatively high content of this 

 organism differentiates its behavior from that of bacteria of low fat content 

 it does so by rendering the tubercle bacillus more resistant to fat solvents 

 and less resistant to substances insoluble in fats." 



Coccidiosis in cattle and carabaos, C. H. ScHtrLTZ {Jour. Infect. Diseases, 

 n (1915), No. 1, pp. 95-108). — ^A discussion of bovine coccidiosis and observa- 

 tions in the Philippines, where it apparently has an extensive distribution. 



