44 APPLIED BACTEETOLOGY 



temperature does not continue to rise, and that the gas in 

 the lantern is not lowered as described, it may be concluded 

 that the heat is insufficient, and a little more gas may be 

 turned on at the cock under the lantern. 



19. The adjustment having been thus effected, nothing 

 remains but to bring the interior up to the temperature 

 desired. 



20. This is effected by sliding the lead weight (which up 

 to this time has been quite to the left) along the lever- 

 rod D, one or two inches at a time at short intervals, until 

 the desired temperature is indicated on the thermometer. 



21. To get at the capsule, hold one hand under it inside 

 the incubator, and with the other unscrew the milled nut 

 which you will find below the screw P. The capsule-holder 

 with the capsule in it will now fall into your hand. 



Do not attempt to regulate the temperature by any ad- 

 justments of the gas-taps, or by altering the adjustments of 

 the milled head-screw P or screw S. The temperature can 

 only be successfully varied by varying the load on the lever, 

 or by the substitution of another capsule having a higher or 

 a lower boiling-point. 



If you require a temperature only a degree or two less 

 than that given when the weight is quite to the left, you 

 may substitute a smaller weight ; but if you require a 

 higher temperature than that given with the weight quite 

 to the right, you must have a capsule acting at a higher 

 temperature. 



If from any cause you suspect that the adjustment of the 

 Excelsior valve has become deranged, open the doors of the 

 incubator and turn out the gas, or pour cold water into the 

 tank until the contents are reduced 5° below the boiling- 

 point of the capsule, and make the adjustment de novo in the 

 same order as before. 



Failure to start the incubator at the first attempt may be 



