HALOID ELEMENTS UPON BACTERIA. 175 



spirillum were placed under a bell jar beside iodoform powder 

 no development occurred, but when they were removed colonies de- 

 veloped, showing that the spirilla were not killed. 



Iodoform Ether, according to Yersin, is fatal to the tubercle ba- 

 cillus in one-per-cent solution in five minutes. Cadeac and Meunier 

 found that a saturated solution required thirty-six hours to kill the 

 bacillus of typhoid fever. 



lodol. In experiments made by the writer (1885) this agent was 

 found to be without germicidal power. Riedlin found it without any 

 action, even upon the cholera spirillum. 



Hydrofluoric Acid, HF1. From a series of experiments made 

 with this gas, Grancher and Chautard arrive at the conclusion that 

 " the direct and prolonged action of hydrofluoric acid upon the tuber- 

 cle bacillus diminishes its virulence but does not kill it." 



Sozoiodol ^4ctd,according to Draer,is a phenol, in which two atoms 

 of hydrogen are replaced by two of iodine and one atom by the group 

 HSO 3 . This acid and its salts with soda, potash, zinc, and mercury 

 have been tested by the author named. The acid and its salt with 

 mercury were found to destroy the cholera spirillum in two hours' time 

 in two-per-cent solution. A two-per-cent solution of phenol would 

 have accomplished the same result and in less time. Tribromphenol, 

 according to Draer, is less active than sozoiodol acid ; and it appears 

 from the experimental evidence on record that combinations of 

 iodine, chlorine, or bromine with phenol are less active that the 

 haloid elements alone. According to Karpow (1893) monochlor- 

 phenol, tested upon anthrax spores attached to silk threads, proved 

 to be decidedly more active than phenol. 



Nosophen (tetraiodphenolphthalein), according to Li even (1895) 

 contains sixty-one per cent of iodine. It is entirely insoluble in 

 water. When added to nutrient gelatin in the proportion of one- 

 quarter per cent it prevented the development of the anthrax bacillus 

 and of Staphylococcus aureus, but failed to prevent the development 

 of Bacillus pyocyaneus (Lieven). 



