ORIGIN OF LOWEST ORGANISMS. 67 



COMPARATIVE EXPERIMENTS. 



IN the following experiments, each fluid (unless a 

 statement is made to the contrary) was boiled con- 

 tinuously for ten minutes, after having been placed in 

 its flask. Then, with the neck either open, sealed, 

 or plugged, the bulb of the flask was immersed in a 

 water-bath maintained at a temperature of 8o-95 F., 

 during both day and night.* 



FIRST SET OF EXPERIMENTS (I.-XV.). 

 a. Fluid exposed to Air in a Flask with a short Open Neck. 



No. I. Urine in twenty-four hours was still clear and free 

 from deposit. In forty-four hours the fluid was very 

 slightly turbid, and on microscopical examination Bac- 

 teria and Torulcz were found, though not in veiy great 

 abundance. In sixty-eight hours the fluid was quite 

 turbid. 



No. II. Hay Infusion in twenty-four hours was still 

 clear. In forty-four hours the fluid was very turbid, and 

 a drop on examination showed multitudes of Bacteria 

 of different kinds, exhibiting languid movements. In 

 sixty-eight hours the turbidity had become much more 



* When infusions have been employed, these have all been 

 made as strong as possible, and have been filtered before use. 

 Warm water has been added in quantity just sufficient to cover 

 the substance to be infused (cut into very small pieces), and the 

 mixture has then been kept at a temperature of from I io-i3o F. 



for three or four hours. 



F 2 



