VITALITY OF PUTREFACTIVE ORGANISMS. 151 



bath. For these experiments eleven closed chambers 

 were prepared, as I wished every result to be based as 

 far as possible upon the testimony of two chambers. 

 On the 6th of last October they were carefully charged 

 with the infusions, the period of boiling afterwards 

 being five minutes. 



Two chambers were devoted to the acid and two to 

 the alkalized infusion of old hay. Two chambers were 

 also devoted to the acid and two to the alkalized infu- 

 sion of dried hay. Two chambers were finally devoted 

 to the alkalized and one to the natural acid infusion of 

 new Heathfield hay. 



Examined from day to day, differences were soon 

 observed, not only between the different infusions, but 

 also between different chambers containing the same 

 infusion. Thus every tube of both the chambers con- 

 taining the neutralized infusion of old hay became 

 turbid, but the three tubes of the one chamber were 

 loaded in four days with a fatty scum, while the tubes 

 of the other chamber remained for ten days perfectly 

 free from scum. The two chambers containing the 

 acid infusion of old hay exhibited similar differences. 

 Every tube in both of them became turbid ; but in one 

 of them the infusion was scumless throughout, while 

 in the other each of the three tubes was heavily laden 

 with scum. 



The two chambers containing the alkalized infusion 

 of dried London hay had all their tubes turbid and 

 covered with scum. In the case of the acid infusion of 

 dried hay, the tubes of one of the chambers became 

 turbid, while the tubes of the other chamber remained 

 clear. 



The two chambers of alkalized new Heathfield hay- 

 infusion were also in disaccord. In the one chamber all 

 three tubes became turbid and covered with scum. 



