126 BACTERIOLOGY. 



side (Fig. 54). The former, z, is of metal, ancLthe latter, a, of glass 

 fitted with a thermometer, the bulb of which, k, is contained within 

 the box. A partition, s, keeps up a current between the openings 



FIG. 55. GAS CHAMBER IN USE WITH APPARATUS FOR GENERATING 

 CARBONIC ACID. 



of the pipes, which are supported on a stand and connected by 

 tubing with the hot-water supply. 



A mixture of paraffine and vaseline is recommended for indicating 

 the temperature of the chamber, and experience has shown that if 

 a temperature of 37 C. is required the temperature of the water 

 in the box must range between 42 and 47 C. 



FIG. 56. GAS CHAMBER. 



Gas Chambers. To investigate the action of gases or vapours 

 upon micro-organisms, a modification of the moist cell may be 

 employed. 



A piece of glass tubing is first fixed to the slide by means of 



