104 



BACTERIOLOGY. 



A more complicated apparatus, combining: both a 

 warm stage and a gas chamber, is shown at Fig. 41. 

 This consists of a rectangular piece of ebonite EE 

 fixed to a brass plate which rests on the stage of the 

 microscope. On the upper surface of the ebonite is 

 another brass plate /, with an aperture c leading 

 into a brass tube closed below by a piece of glass. 

 To heat the apparatus the copper wire B is placed 



FIG. 40. GAS CHAMBER IN USE WITH APPARATUS FOR GENERATING 

 CARBONIC ACID. 



on the tube a, and its extremity heated by the flame 

 of the lamp. The nearer the lamp to the stage 

 the higher the temperature, which is indicated by 

 the thermometer t. To employ it as a gas chamber 

 the wire B is laid aside and the gas is conducted 

 into the chamber by the tube a and escapes by the 

 tube a. 



Application of Electricity. To study the 



