il6 LIQUID CULTIVATING MEDIA. 



water or air rises high, a column of mercury in the regulator rises also 

 to such an extent as to cut off nearly all the gas supply which 

 passes through the regulator to the burner. In this way the flame 

 is reduced, and the temperature of. the water begins to fall; as if 

 does so, the column of mercury falls, and more gas is permitted to 

 pass. By these two processes of mutual accommodation it is usually 

 easy to maintain a very equable temperature in the incubator. To 

 cultivate many species of organisms successfully it is necessary to 

 incubate the media in which they are. Generally speaking, a tem- 

 perature of from 30° to 36° C. is the most advantageous for inducing 

 a rapid development of the cultivated organisms. 



