VITALITY 01^' PUTKEFACTIVE OEGANISMS. 229 



was contained in tubes drawn out finely at the end, 

 which were introduced into the flasks containing the 

 urine, and broken by shaking after the acid urine had 

 been completely sterilized by heat. The cases were ex- 

 ceedingly rare in which life showed itself in the urine 

 thus neutralized. The preponderance of sterilized flasks 

 over unsterilized ones was very great. 



In the experiments now to be glanced at, neither 

 the urine nor the potash was raised to a temperature 

 higher than 212°. Wishing to ascertain how the refrac- 

 tory germs of our laboratory would fare in neutralized 

 urine, on the 1 6th of February I had five pipette-bulbs 

 charged with the liquid. It was neutralized by caustic 

 potash, which on boiling produced copious precipitation. 

 It was afterwards filtered and rendered very transparent. 

 The bulbs had been well cleansed, filled with one-third 

 of an atmosphere of filtered air, hermetically sealed, 

 and exposed afterwards to the heat of a Bunsen flame^ 

 They were charged with the urine by breaking off their 

 finely drawn out points in the body of the liquid. They 

 were then again sealed, and subjected to the boiling 

 temperature for ten minutes. 



Not one of these bulbs remained sterile. Two days 

 subsequent to their preparation they were all swarming 

 with organisms. 



Three other bulbs were on the same occasion charged 

 with precisely the same infusion, only instead of being 

 associated with air they were well purged of air by five 

 minutes' boiling in an oil-bath. While the steam was 

 issuing they were hermetically sealed. 



Not one of these bulbs has proved fruitful. They are 

 all as brilliant and as free from life as they were after 

 they had passed through the filter. 



The difference here indicated is worthy of notice. 

 In the one case five minutes' action completely steril- 



