ACTIONS OF CERTAIN ANTISEPTICS 145 



chlorous acid is formed, and the effect produced is thus similar 

 to that of bleaching powder. Nissen, investigating the action of 

 the latter, found that 1^ per cent killed typhoid bacilli in faeces ; 

 and Rideal found that 1 part to 400-500 disinfected sewage in 

 fourteen minutes, and Delepine's results show that 1 part to 50 

 (equal to '66 per cent of chlorine) rapidly kills the tubercle 

 bacillus, and 1 part to 10 (equal to 3 '3 per cent) killed anthrax 

 spores. Klein found that *05 per cent of chlorine killed most 

 bacterial spores in five minutes. 



Iodine Terchloride. This is a very unstable compound of 

 iodine and chlorine, and though it has been much used as an 

 antiseptic, seeing that the- substance only remains as IC1 3 in 

 an atmosphere of chlorine gas, it is open to doubt whether the 

 effects described are not due to a very complicated action of 

 free hydrochloric acid, hydriodic acid, of oxyacids of chlorine 

 and iodine produced by its decomposition, and also, in certain 

 cases, of organic iodine compounds formed from its contact with 

 albuminous material. It is stated that the action is very potent : 

 a 1 per cent solution is said instantly to kill even anthrax spores, 

 but if the spores be in bouillon, death occurs after from ten to 

 twelve minutes. In serum the necessary exposure is from thirty 

 to forty minutes. A solution of 1-1000 will kill the typhoid, 

 cholera, and diphtheria organisms in five minutes. 



Nascent Oxygen. This is chiefly available in two ways firstly, 

 when in the breaking up of ozone the free third atom of the 

 ozone molecule is seeking to unite with another similar atom ; 

 secondly, when peroxide of hydrogen is broken up into water 

 and an oxygen atom is thereby liberated. In commerce the 

 activity of " Sanitas " compounds is due to the formation of 

 ozone by the slow oxidation of the resin, camphor, and thymol 

 they contain. 



Per chloride of Mercury. Of all the salts of the heavy metals 

 this has been most widely employed, and must be regarded as 

 one of the most powerful and useful of known antiseptics. In 

 testing its action on anthrax spores there is no doubt that in the 

 earlier results its potency was overrated from a neglect of the 

 fact already alluded to, that in the spore-case an albuminate of 

 mercury was formed which prevented the contained protoplasm 

 from developing, while not depriving it of life. It has been 

 found, however, that this salt in a strength of 1-100 will kill the 

 spores in twenty minutes, although an hour's exposure to 1-1000 

 has no effect. The best results are obtained by the addition to 

 the corrosive sublimate solution of -5 per cent of sulphuric acid 

 or hydrochloric acid ; the spores will then be killed by a seventy- 

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