666 CONDITIONS AFFECTING THE DEATH OF FUNGI. 



Trustworthy 

 disinfecting 

 means must 

 destroy 

 spores. 



Experiments 

 with anthrax 

 spores. 



a knowledge of the proportions necessary for destroying 

 bacteria free from spores is of comparatively little 

 importance ; in many cases we have to do with infective 

 agents which undoubtedly form spores, in other cases 

 the infective agents are not accurately known, and the 

 possibility of the formation of resting forms is doubtful. 

 Complete trust can therefore only be placed in those 

 methods which can destroy any spores which may pos- 

 sibly be present. It is therefore of chief practical 

 importance to test the disinfecting media with regard to 

 their action on spores. 



In this respect a series of experiments made by Koch is 

 worthy of note, these experiments having been made by 

 the comparison of various chemical poisons as regards 

 their action on the same object for example, on anthrax 

 spores. The following are the most important results 

 of these experiments : 



1. The following substances had no action on anthrax 

 spores, even after acting for several months : 



Distilled water 



Absolute alcohol 



Chloroform 



Glycerine 



Benzole 



Benzoic acid (concentrated watery solution) 



Salicylic acid (5 per cent, in alcohol, 2 per cent, in oil) 



Thymol (5 per cent, in alcohol) 



Ammonia 



Salt solution (concentrated) 



Chloride of calcium solution (concentrated) 



Chlorate of potash (5 per cent, in water) 



Alum (4 per cent, in water) 



Borax (5 per cent, in water) 



Potash soap (2 per cent, in water). 



2. The following showed incomplete or slow action 

 on anthrax spores : 



Ether (incomplete action after eight days, complete 



action after thirty days) 

 Acetone (incomplete after five days) 

 Iodine, 1 per cent, in alcohol (incomplete after one day) 



