THEORIES AS TO THE ORIGIN OF LIFE. 87 



sively disproving the hypothesis of spontaneous 

 generation by subjecting it to the experimentum 

 crucis. Two vessels were filled with distilled 

 water, and in them were placed various animal 

 and vegetable substances. One vessel was left 

 uncovered, the other was firmly closed, and 

 treated by a peculiarly trying process for de- 

 stroying and excluding all life, by boiling, &c., 

 while the air was renewed in it, after being 

 filtered of any germs that might be in it^by 

 passing through a red-hot tube, and strong sul- 

 phuric acid. " Thus every living thing," says 

 Schultz, " and all germs in the vessel all por- 

 tions of living matter, or of matter capable of 

 becoming animated, were destroyed/' The open 

 vessel on the second day contained Vibriones 

 and Monads, to which were soon added Poly- 

 gastrica and Eotatoria. " From the 28th of 

 May till the beginning of August/' says Schultz, 

 " I watched the closed vessel, without being 

 able, by the aid of the Microscope, to perceive 

 any living animal or vegetable substance. When 

 at last, I separated the different parts of the 

 apparatus, / could not find in the whole liquid 

 the slightest trace of Infusoria, of Conferva, or 

 of Mould. But all the three presented them- 



