255 



TRANSLATIONS. 



On the Origin of Ferments. New experiments relative to 

 so-termed Spontaneous Generation. By M. L. Pasteur. 



(' Comptes Rendus,' May 7, I860, p. 849.) 



Among the questions arising during the researches which 

 I have undertaken on the subject of fermentations properly 

 so termed, there is none more worthy of attention than that 

 which relates to the origin of "ferments." Whence proceed 

 these mysterious agents, so feeble in appearance, and yet in 

 reality so powerful; which in the minutest quantity, mea- 

 sured by weight, and with insignificant external chemical 

 characters, possess such extraordinary energy ? It is in an 

 attempt to solve this problem that I have been led to the 

 study of the so-termed spontaneous generation. 



In the communication which I had the honour of sub- 

 mitting to the Academy on the 6th of February last, I men- 

 tioned only a single fluid appropriate for the development of 

 Infusoria and Mucedinea, although I gave a general method 

 applicable to all liquids. 



On that occasion I showed, in a manner that has been 

 contested only in appearance — First, that the solid parti- 

 cles conveyed in the atmospheric air were the origin of all 

 the vegetable and animal productions peculiar to the fluid in 

 question. Secondly, that these particles, examined under 

 the microscope, are amorphous, dusty atoms, constantly 

 associated with certain corpuscles, whose form, volume, and 

 structure show that they are organized after the manner of 

 the ova of Infusoria or of the spores of the Mucedinea. 



I am, at present, in a condition to extend the assertions 

 contained in the communication of the 6th February to two 

 substances, still more alterable than the sugared water mixed 

 with albuminous matters which had been more particularly 

 the subject of my former experiments. 1 now speak of 



