OXYGEN RESPIRATION 



35 



is considerably narrower. The line O is cut only on the right 

 side of the measuring tube and level with the line Im on the 

 mercury bath C. 



The mercury bath C and the two gas pipettes D and E are 

 joined, by thick-walled rubber tubes and a T-tube, with the 

 large pear-shaped bulb G, the volume of which is approxi- 



FiG. 6. — The Polowzow-Richter apparatus. 



mately the same as that of the bath. If the two glass stop- 

 cocks n and ^ are closed, it is possible either to empty or to fill 

 the bath C with mercury by means of the opened pinchcock 

 M, according to the position of the pear-shaped bulb. With the 

 pinchcock M closed, one is able, by means of the bulb G and 

 the two glass stopcocks n and p, to cause mercury to flow 



