Comparative Poiuer of some Disinfectants. 101 



developed an abundant mycelial growth in several instances 

 where the bacteria had undoubtedly been killed, it is evident 

 that they possessed greater powers of resistance. In the 

 detailed notes of my experiments I find that the mould 

 appeared on paper which had been exposed to the vapour of 

 carbolic acid for as long as 8 hours, a period of 3 J to 5 being 

 sufficient for the destruction of the bacteria. On none of the 

 pieces exposed to the fumes of burning sulphur was there 

 any growth of mycelium. The ozonic vapour, again, though 

 capable of destroying bacteria exposed to ft for 10 or 15 

 minutes, apparently had not injured the spores of the fungus 

 after 60 minutes. Again, whilst the chlorine killed the bac- 

 teria when applied for something over an hour, two pieces of 

 paper, exposed to it for 3 and 4J hours respectively, showed 

 a copious growth of mould. Even to heat the penicillium 

 spores showed greater power of resistance. Thus the 

 mycelium appeared on each of the two pieces of paper which 

 had been treated for 15 and 30 minutes respectively, the 

 bacteria being killed in both instances. None appeared on 

 the paper which had been treated for 45 minutes. 



The conclusion to which I am brought, therefore, by the 

 concurrent results of all these experiments is, that the spores 

 of fungi are less easily destroyed than dried septic organisms, 

 and presumably than dried contagium of zymotic diseases — 

 as Dr. Baxter's experiments with dried vaccine showed its 

 power of causing cow-pox to be destroyed by carbolic vapour 

 in about 30 minutes, by sulphurous acid in 10 minutes, by 

 chlorine in 30 minutes, and by a dry heat of 185° to 194° 

 Fahr. for 26 minutes. He ventures to express the opinion 

 — founded not on his own experiments, but on a few made 

 by others on yeast and penicillium — that the influence of 

 disinfectants on such fungoid spores afibrds no measure of 

 their action on contagia, since the former are very much 

 more susceptible to adverse influences than the latter. This 

 opinion is directly contradicted by the results of the exact 

 experiments here detailed, which show that any disinfectant 

 which destroys penicillium. spores in the dry state may be 

 depended on to destroy bacteria, and so_, presumably, con- 

 tagia, which are even more easily destroyed, as a comparison 

 of my observations with Dr. Baxter's on vaccine clearly 

 shows, 



