172 -Appendix. 



An important, if indeed it be not the pivotal point in the 

 recent discussions of this question, is the degree of heat to which 

 vegetable and animal germs can be submitted without destroying 

 their vitality. On this point there is great discrepancy of opin- 

 ion. To admit that 212 F. is insufficient, is to destroy absolute- 

 ly, as Pouchet pointed out, the validity of Spallanzini's and Schul- 

 tze's experiments. I allude to this, not for argument's sake, which 

 is foreign to a historical review of the question, but merely to 

 enable me to state several interesting facts. Prof. Jeffries Wyman*, 

 of Harvard College, found infusoria in infusions that had been 

 boiled four hours, but he found none after five or six hours boiling. 



kind of superstition which is constantly receding before the advance of the 

 natural sciences.'' Text-Book of Physiology. London, 1853, p. 624. 



POUCHET, in his Heterogenie, previously alluded to, (p. 162) deliberately 

 quotes Valentin as a supporter of his (Pouchet's) views, whereas he is an un- 

 compromising opponent of them. 



VAN BENEDEN: " It is evident to all those who place facts above hypothe- 

 ses and prejudices, that spontaneous generation, * * * does not exist, at 

 least if we only consider the present epoch." Animal Paras Ites and Messmates, 

 p. 106. 



CAKPENTEB, W, B.: "The doctrine of 'spontaneous generation' cannot 

 now be said to have any claim whatever to be received as even a possible hy- 

 pothesis." Principles of Physiology, Genl. and Oomp., 3d edition, Philadelphia, 

 1851, p, 866. 



HUIZINGER: ' Under the above described circumstances [i. e. his experi- 

 ments] Bacteria can arise without pre-existing germs. Not in any single 

 case have I seen any other organisms than Bacteria never fungi." X<tt ><', 

 March 30, 1873, p. 381. 



JAMES SAMUELSON: "If the believers in spontaneous generation still in- 

 sist that their hypothesis has not been refuted and that, assuming rny obser- 

 vations to be correct, their view of the case has not been fully disproved, 1 

 am not prepared to deny this. But, on the other hand, I must be permitted 

 to retort that their experiments have only proved, so far, their inability, not- 

 withstanding all their precautions, to exclude invisible germs from their in- 

 fusions.''.^^. Times and Gazette, Sept. 24, 1870, p. 376. 



TYNDAI.L : " As far as inquiry has hitherto penetrated, life has never been 

 proved to appear independently of antecedent life." Nature, February 3, 

 1876, page 269. 



* PROF. WYMAN'S experiments are justly deemed among the most valu- 

 able contributions ever made to this subject. They are recorded in the 

 Amer. Jour, of Sci. and Arts, Vol. XXXIV, 1862, p. 79, and Vol. XLIV, 1867, 

 p. 152. 



