330 FRAGMENTS OF SCIENCE. 



in this case infects itself without special inoculation, 

 and its subsequent resistance to sterilisation is often 

 very great. On the 1st of March last I purposely in- 

 fected the air of our laboratory with the germinal dust 

 of a sapless kind of hay mown in 1875. Ten groups of 

 flasks were charged with turnip infusion prepared in 

 the infected laboratory, and were afterwards subjected 

 to the boiling temperature for periods varying from 

 15 minutes to 240 minutes. Out of the ten groups 

 only one was sterilised that, namely, which had been 

 boiled for four hours. Every flask of the nine groups 

 which had been boiled for 15, 30, 45, 60, 75, 90, 105, 

 120, and 180 minutes respectively, bred organisms 

 afterwards. The same is true of other vegetable in- 

 fusions. On the 28th of February last, for example, I 

 boiled six flasks, containing cucumber infusion prepared 

 in an infected atmosphere, for periods of 15, 30, 45, 60, 

 120, and 180 minutes. Every flask of the group sub- 

 sequently developed organisms. On the same day, in 

 the case of three flasks, the boiling was prolonged to 

 240, 300, and 360 minutes ; and these three flasks were 

 completely sterilised. Animal infusions, which under 

 ordinary circumstances are rendered infallibly barren 

 by five minutes' boiling, behave like the vegetable in- 

 fusions in an atmosphere infected with hay-germs. On 

 the 30th of March, for example, five flasks were charged 

 with a clear infusion of beef and boiled for 60 minutes, 

 120 minutes, 180 minutes, 240 minutes, and 300 

 minutes respectively. Every one of them became sub- 

 sequently crowded with organisms, and the same hap- 

 pened to a perfectly pellucid mutton infusion prepared 

 at the same time. The cases are to be numbered by 

 hundreds in which similar powers of resistance were 

 manifested by infusions of the most diverse kinds. 

 In the presence of such facts I would ask my 



