2 



Mr. J. Thompson. Action of 



[Aug. 27, 



containing the medium under examination, and the flask (g), containing 50 c.c. 

 of a 10 per cent, solution of caustic potash, are connected with the taps of 

 the burettes as shown in the diagram, by stout rubber connections at (t) and 

 (s). The internal capacity of the flask and incubation tube and connecting 

 tubes between the taps (h) and (i) was determined. Deducting the volume 

 of medium and caustic potash solution, the volume of air contained in them 

 at the beginning of the experiment is known. 



The burettes and receivers having been charged with mercury, the 



incubation tube (/), containing 10 c.c. of the medium, previously sterilised 

 and subsequently inoculated from a culture of B. cloacce on the same 

 medium, is connected to the burette (5) and the absorption flask (g). The 

 tap (i) is removed, and, about 80 c.c. of air having been allowed to flow into 

 the graduated burette, the tap is replaced in connection with the tube (/). 

 By suitable manipulation of the receivers (d) and (e) and the two-way taps, 

 the liquid in the tubes (m) and {n) is brought to the level of the liquid in 

 (/) and (g). The volume of air, thus brought to atmospheric pressure, is 

 then read off on the burette (b), the temperature and barometric pressure 

 being carefully noted. The tap (A) is now opened to the flask (g), the 



