16 MICRO-OKGANISMS AND FERMENTATION. 



tant than it is commonly held to be. A solution containing 5 

 per cent, destroyed the power of development of anthrax spores 

 only after 48 hours, whilst the anthrax bacilli were killed in 

 two minutes by a 1 per cent, solution. A solution of 1 part in 

 850 proved sufficient to check the growth of the bacillus, and 

 when anthrax spores were moistened 5 to 7 times with a 5 

 per cent, solution, their development was somewhat retarded. 

 A 5 per cent, solution of carbolic acid in oil or alcohol had 

 absolutely no effect on the anthrax cells and spores. In the 

 form of vapour, carbolic acid acts more strongly, although even 

 two hours' action of its vapour at 75 C. proved unable to 

 destroy the vitality of these spores. Sulphurous acid is not 

 able to destroy all germs, even under very favourable conditions. 

 On the other hand, chlorine, bromine, and corrosive sublimate 

 are efficient disinfectants. According to KOCH, corrosive sub- 

 limate in the proportion of 1 in 1000 acts fatally on all germs. 

 According to experiments made by JOHAN-OLSEN, however, 

 mould-fungi are only destroyed by more concentrated solutions ; 

 e.g., Penicillium glaucum only by a solution containing 1 in 

 400. Several bacteria, the organisms of puerperal fever, 

 abscesses, and putrefaction, likewise germinate and grow, 

 although more slowly than usual, on slices of potato saturated 

 with a solution of sublimate containing 1 part in 500, and 

 their growth is only checked by a concentration of 1 in 300 

 under these circumstances. GRUBER found from recent investi- 

 gations, carried out with all precaution, that anthrax spores, for 

 instance, were only killed by 5 parts of sublimate in 1000, 1 

 part of sublimate hydrochloric acid in 1000, 1 part of sub- 

 limate tartaric acid in 1000. A disinfectant of common 

 industrial use is milk of lime, which in a fresh state is very 

 effective. 



For cleansing pipes, coolers, etc., which often contain very 

 considerable deposits of organic matter liable to decomposition 

 through the agency of micro-organisms, a solution of soda is to 

 be recommended ; it acts by dissolving and loosening resinous 

 and albuminoid matters, which can then be removed by means 

 of water. The daily cleansing of conduits and india-rubber 

 hosepipes must always be effected by steaming. Experiments 

 made by AUBRY and WILL have proved that chloride of lime, 



