170 ANTISEPTICS 



cerned in their solution, especially when they are electrolytes, 

 probably play a part in their action. The part played by such 

 factors is exemplified in the important fact that a strong solution 

 acting for a short time will have the same effect as a weaker 

 solution acting for a longer time. From what has been said it 

 will be realised that the real causes of a material being an 

 antiseptic are very obscure, and at present we can only have a 

 remote idea of the factors at work. 



The Effects of certain Antiseptics. Here we can only 

 briefly indicate certain results obtained with the more common 

 members of the group. 



Chlorine. All the halogens have been found to be powerful 

 antiseptics, but from the cheapness with which it can be produced 

 chlorine has been most used ; not only is it the chief active 

 agent in the somewhat complex action of bleaching powder, but 

 it is also the chief constituent of several proprietary substances, 

 of which " Electrozone " is a good example. This last substance 

 is made from electrolysing sea- water, when magnesia, and chlorine 

 being liberated, magnesium hypochlorite and magnesium chloride 

 are formed. In the action of this substance free hypochlorous 

 acid is formed, and the effect produced is thus similar to that 

 of bleaching powder. Nissen, investigating the action of the 

 latter, found that 1J 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, seeing that the substance only remains 

 as IC1 3 in an atmosphere of chlorine gas, it is open to doubt 

 whether the antiseptic effects attributed to it 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, 



