SPONTANEOUS GENERATION 347 



But, instead of choosing a putrefying liquid for inocu- 

 lation, let us prepare and employ our inoculating sub- 

 stance in the following simple way: Let a small wisp of 

 hay, desiccated by age, be washed in a glass of water, and 

 let a perfectly sterilized turnip infusion be inoculated with 

 the washing liquid. After three hours' continuous boil- 

 ing the infusion thus infected will often develop luxuri- 

 ant bacterial life. Precisely the same occurs if a turnip 

 infusion be prepared in an atmosphere well charged with 

 desiccated hay-germs. The infusion in this case infects 

 itself without special inoculation, and its subsequent re- 

 sistance to sterilization is often very great. On the 1st 

 of March last I purposely infected the air of our labora- 

 tory 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 after- 

 ward subjected to the boiling temperature for periods vary- 

 ing from 15 minutes to 240 minutes. Out of the ten 

 groups only one was sterilized 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 

 afterward. The same is true of other vegetable infusions. 

 On the 28th of February last, for example, I boiled six 

 flasks, containing cucumber infusion prepared in an in- 

 fected atmosphere, for periods of 15, 30, 45, 60, 120, "and 

 180 minutes. Every flask of the group subsequently de- 

 veloped organisms. On the same day, in the case of three 



between water-germs and air- germs; the growth from the already softened 

 water-germs proving to be practically as rapid as from developed bacteria. Thia 

 preparedness of the germ for rapid development is associated with its prepared- 

 ness for rapid destruction. 



