ANAEROBIC CULTURES 



239 



METHOD. 



1. Prepare the tube cultivation in the usual way. 



2. Moisten the india-rubber stopper of the Buchner's 

 tube with water and see that it fits the mouth of the 

 tube accurately. 



3. Remove the stopper from the caustic soda bottle. 



4. Drop one of the pyrogallic acid tablets into the 

 Buchner 's tube (roughly, use i gramme pyrogallic acid 

 for every 100 c.c. air capacity of the receiving vessel). 



5. Add about i c.c. of the soda solution. 



6. Place the inoculated tube inside the Buchner's 

 tube. The pyrogallic tablet acts as a 



buffer and prevents damage to either 

 the inoculated tube or the Buchner's 

 tube even should it be slipped in hur- 

 riedly. 



7. Fit the india-rubber stopper tightly 

 into the mouth of the Buchner 's tube. 



The pyrogallic acid tablet dissolves 

 slowly in the soda solution and its oxida- 

 tion proceeds very slowly at first so that 

 ample time is available when this method 

 is adopted. 



8. Restopper the caustic soda bottle. 



9. Place Buchner's tube in a wire sup- 

 port, and incubate. 



the 



FIG. 130. Buch- 

 ner's tube. 



Method VII (Wright 's Method) .- 



1. Prepare tube cultivation in 

 usual way. 



2 . Cut off that portion of the cotton- wool plug project- 

 ing above the mouth of the tube with scissors, then 

 push the plug into the tube for a distance of 2 or 3 cm. 



1 If compressed tablets of pyrogallic acid cannot be obtained make up a 

 stock "acid pyro" solution 



Pyrogallic acid, 10 grammes 



Hydrochloric acid, 1.5 c.c. 



Distilled water, 100 c.c. 

 and at step 4, run in 10 c.c. of the solution. 



