650 THE POPULAR SCIENCE MONTHLY. 



are tubes of alkalized hay, some of them subjected to a boiling tem- 

 perature, not for three hours, but for ten minutes, and they are per- 

 fectly brilliant ; there is not the slightest evidence of life in them ; 

 they have been entirely sterilized by an exposure to a boiling tempera- 

 ture for ten minutes. If I illuminate them, you will find that these 

 infusions are perfectly brilliant ; there is no turbidity that gives any 

 sign of the production of animalcular life. These tubes have remained 

 there for three months perfectly intact, uninvaded by those organisms 

 which were invariably found both by Dr. Roberts and by Prof. Cohn. 

 Again, we turn to another series of tubes, and find that every one of 

 them has given way. Thus I went on ringing the changes, until, as 

 I have said, it was in my power, by pursuing with undeviating fidelity 

 the mode of experiment laid down by Dr. Roberts and Prof. Cohn, to 

 get at one time a contradiction, and at another time a corroboration 

 of their results. 



And what was the meaning of these irreconcilable contradictions? 

 The meaning was this : when we came to analyze these various in- 

 fusions, we found that those that were sterilized by a boiling of from 

 five to ten minutes were invariably infusions of hay mown in the year 

 1876, whereas the others were infusions of hay mown in 1875 or some 

 previous year. The most refractory hay-infusion that I have ever 

 found was in the case of some Colchester hay five years old. Now, 

 what do these experiments point to ? The answer may be in part 

 gathered from an observation described in the volume of the Comptes 

 Hendus for 1863, by one of the greatest supporters of the so-called 

 doctrine of spontaneous generation. A description is here given of 

 an experiment that was made by the wool-staplers of Elbceuf. They 

 were accustomed to receive fleeces from Brazil, which were very dirty, 

 and had, among other things, certain seeds entangled in them. These 

 fleeces were boiled at Elboeuf sometimes for four hours ; and the seeds 

 were afterward sown by some of these expert fellows that had to deal 

 with the fleeces, and were found capable of germination. The thing was 

 taken up by Pouchet. He gathered these seeds, exposed them to the 

 temperature of boiling water for four hours, and then examined them 

 closely ; and he found (and I recently made an experiment which 

 showed the same thins: to be true with regard to dried and undried 

 peas) that the great majority of the seeds were swollen and disorgan- 

 ized, while the others were scarcely changed ; they were so indurated, 

 and perhaps altered in the surface, as to prevent the liquid from wet- 

 ting them. At all events, a number of them appeared to be quite 

 unchanged. He separated these two classes of seeds and sowed them 

 side by side in the same kind of earth. The swollen seeds were all 

 destroyed; there was no germination; but in the case of the others 

 there .was copious germination. Here, then, you have these seeds 

 proved to be capable, by virtue of their dryness and induration, of 

 resisting the temperature of boiling water for four hours. There is 



