2p2 METHODS OF IDENTIFICATION AND STUDY 



An Orsat-Lunge working with mercury instead of water, 

 provided with two gas tubes of extra length (capacity 120 and 

 60 c.c. respectively and graduated throughout, both being water- 

 jacketed) or other gas analysis apparatus, capable of dealing with 

 C0 2 , 2 , H 2 , and N 2 . 



METHOD. 



i. Inoculate the medium in the flask in the usual 

 manner, by means of a platinum needle, taking care 

 that the neck of the flask and the rubber stopper are 



FIG. 154. Orsat-Lunge gas analysis apparatus. 



thoroughly flamed before and after the operation. 



2. Fill the iron cylinder with mercury. 



3. Place the bell jar mouth downward in the 

 mercury first seeing that there is free communication 



between the interior of the jar and the external air and 



suck up the mercury into the tap ; then shut off the tap. 



4- Plug the open end of the three-way tap with 

 melted wax. 



5- Connect up the horizontal arm of the culture 

 flask with that of the gas receiver by means of the 



