a Pasteur on Spontaneous Generation. 
Fermentation of Urine —A flask with an attenuated neck was 
one-third filled with fresh urine and boiled for three or four 
minutes and then allowed to cool with no access of air except 
what was drawn through a platinum tube heated to redness. 
When cool the flask was hermetically sealed and the enclosed 
urine was thus exposed only to atmospheric air deprived by heat 
of all viable germs. In this condition the urine remained for 
months without change. Into a flask thus prepared, asbestos 
charged with atmospheric dust was introduced by the method 
above described. The flask was kept at 86° F., and in about 
six hours mucedines and infusoria appeared, among which were 
Bacteria, Vibriones and Monads, the same as appeared in similar 
urine exposed to the open air. During the following days lith- 
ates and crystals of triple phosphate were deposited, the urine 
became ammoniacal and its urea disappeared under the influence 
of the true ferment of the urine, which Pasteur believes to be or- 
ganized, and whose germ, could only have been introduced in the 
atmospheric dust in connection with the germs of infusoria and 
mucedines. When a flask prepared in the same manner had 
only calcined asbestos introduced, without atmospheric dust, 
neither mucedines nor infusoria appeared, neither did any fer- 
mentation take place however long the flask was permitted to re- 
main unopened. 
Coagulation of milk.—Fresh milk was boiled in a flask for two 
e common theory that milk coagulates in consequence of 
the formation of lactic acid is an error. It is also shown that 
vibrios may appear in milk which has undergone ebullition for 
several minutes at 212° F., although urine or a solution of sugar 
and albumen does not produce vibrios under such conditions. 
In other experiments the milk was boiled for longer periods un- 
der a pressure of 14 atmospheres at a temperature of 230° or 235° 
F., and the flasks were sealed as before. Flasks thus prepared 
furnished no infusoria, the milk did not coagulate however long 
it remained enclosed in the flasks, it remained alkaline even with 
the presence of oxygen in the form of calcined air as stated 
pie and it preserved apparently all the properties of fresh 
milk. ‘ 
Into flasks of milk thus prepared Pasteur introducéd atmo: 
spheric dust by the method detailed above, when the milk congu- 
va 
