The Origin of Infusoria. 323 



of the same decoction, together with, air that had been passed 

 through red-hot tubes {air calcine). Then, following the method 

 of M. Pasteur, they caused a little tube containing gun-cotton, 

 charged with dust from the air, and " subjected to the action of 

 burnt air/' to fall into flask A. The neck of the flask, also filled 

 with the burnt air, was sealed in a lamp. In flask B, prepared 

 in the same way, they placed a piece of gun-cotton, selected 

 from the middle of a considerable mass of that material which 

 had been kept in a closed bottle, and was as free as possible 

 from atmospheric dust particles. In they placed the same 

 decoction, with calcined air, and no cotton, while D was sub- 

 jected, like the preceding, to a second ebullition, but was allowed 

 to remain open. A fifth, B, was closed during the second boiling. 

 After five days A was opened, and found to contain long Bac- 

 teriums, and a clot of a branching and entangled mycelium. 

 This was the result obtained by M. Pasteur. B was opened two 

 days later, and contained what the writers call dead Bacteriums 

 reduced to granulations, and on a portion of the gun-cotton which 

 extended beyond the tube there was a fine mycelium identical 

 with that in A. C was opened on the same day with A, and ex- 

 hibited Bacteriums, but rather fewer than A, and no mycelium. 

 " This result, - " say MM. Joly and Musset, " confirms once more 

 those which we obtained last year, in repeating the experiment 

 of Schwann, and it proves, contradicting the assertions of M. 

 Pasteur, that air heated and then cooled does not leave intact the 

 juice of meat which has been exposed to ebullition. On the 

 sixth day, D, which had remained open, exhibited no infusoria, 

 but two days later swarmed with long and active Bacteriums. 

 Eight days later E exhibited no infusorial life. Another 

 set of experiments showed that distilled water containing a tuft 

 of gun-cotton charged with atmospheric dust produced few 

 organisms, and sometimes none ; that similar water, to which a 

 considerable quantity of dust was added, yielded Bacteriums and 

 monads ; that if aster leaves, carefully washed in pure water, 

 were placed in distilled water, ciliated infusoria appeared. Dis- 

 tilled water used to wash a large quantity of mercury from a 

 pneumatic trough "remained unfertile, although one of the 

 enemies of heterogeny affirmed that a single globule of mercury 

 was enough to people any infusion.'" 



Following M. Pouchet, MM. Joly and Musset placed a 

 considerable quantity of a filtered infusion of chopped hay in one 

 vessel, and then floated in it a smaller vessel containing some of 

 the same infusion. In the large vessel they obtained ciliated 

 infusoria, and only Bacteriums and monads in the little one. It 

 is not stated how long they kept these vessels to see what they 

 would yield. 



It is possible that after a greater lapse of time ciliated in- 



