174 ACTION OP GASES AND OF THE 



pneumonia* crouposa^in the proportion of I : 1,000, and to the staphy- 

 lococci of pus in 1 : 500 time of exposure two hours. Iodine water 

 was found by Koch to destroy the vitality of anthrax spores in 

 twenty-four hours, but a two-per-cent solution in alcohol failed to 

 destroy anthrax spores in forty-eight hours. In the experiments of 

 Schill and Fischer twenty hours' contact with a solution of the 

 strength of 1 : 500 failed to destroy the virulence of tuberculous spu- 

 tum, as tested by inoculation experiments. The antiseptic value of 

 iodine is given by Miquel as 1 : 4,000. 



Bromine. Fischer and Proskauer have studied the action of 

 bromine vapor upon various microorganisms. They found that ex- 

 posure for three hours in a dry atmosphere to three per cent does 

 not destroy the tubercle bacillus in sputum or the spores of an- 

 thrax. But when the atmosphere is saturated with moisture 1 : 500 

 is effective ; and when the time of exposure was extended to twenty- 

 four hours, 1 : 3,500. A two-per-cent solution destroys the vitality 

 of anthrax spores in twenty-four hours (Koch). Bromine vapor is 

 an active agent for the destruction of the virus of symptomatic an- 

 thrax (Arloing, Cornevin, and Thomas). Miquel gives the antisep- 

 tic value of bromine as 1 : 1,666, which is considerably below that of 

 chlorine and iodine. 



Iodine Trichloride. According to Behriiig, we possess in this 

 agent a disinfectant which possesses the potency of free chlorine and 

 iodine without having their disadvantages. As prepared by O. Rie- 

 del it is a yellowish-red powder of penetrating odor. It remains un- 

 changed for weeks in concentrated aqueous solution (five per cent). 

 A one-per-cent solution destroys anthrax spores suspended in water 

 almost instantly, and a 0.2-per-cent solution within a few minutes. 

 Anthrax spores in blood serum are killed by a one-per-cent solution 

 in forty minutes (Behring). Langenbuch found that a solution of 

 1 : 1 ,000 kills spores in a short time, and that when added to nutri- 

 ent gelatin in the proportion of 1 : 1,200 it restrains the develop- 

 ment of bacteria. 



lodoform. Numerous experiments have been made with this 

 agent, which slm\v that it has little, if any, germicidal power ; but 

 it acts to some extent as an antiseptic. Tilanus reports that the tu- 

 bercle bacillus will not grow in glycerin-agar cultures to which a 

 small quantity of iodoform has been added, and that a pure culture 

 of the tubercle bacillus was not killed in six days by exposure to 

 iodoform vapor, but that after six weeks* exposure it failed to grow. 

 The experiments of Neisser and of Buchner show that while most 

 bacteria are not injuriously affected by exposure to iodoform vapor, 

 the cholera spirillum and the Finkler-Prior spirillum are restrained in 

 their growth by such exposure. When plate cultures of the cholera 



