372 



MEDICAL BACTERIOLOGY 



In the second method (Buehner's method) an alkaline solution 

 .of pyrogallic acid is used to absorb the oxygen. The cultures may 

 be placed in Novy jars or similar receptacles; for tube cultures a 

 large wide mouthed bottle fitted with a rubber cork does very well. 

 The dry pyrogallic acid is placed in the bottom of the receptacles, 

 about 1 gram to every 100 cc. of air space, the tubes are put in place, 

 then about 10 cc. of a normal sodium hydroxide solution are added 

 to each gram of pyrogallic acid, and the apparatus immediately and 

 hermetically sealed. A very convenient method has recently been 

 outlined by Wright for test-tube cultures. It is as follows : After 

 the culture medium has been inoculated in 

 the usi^al manner, thrust the cotton plug 

 into the test-tube so that the upper end of 

 the cotton is about 2 cm. below the mouth 

 of the test-tube (it is usually desirable to 

 cut off a part of the protruding portion 

 before doing this). Fill the tube with py- 

 rogallic acid. Add with a pipette enough 

 of a 4% solution of sodium hydrate to dis- 

 solve the acid. Close the tube immediately, 

 making it air tight by inserting a rubber 

 stopper in its mouth. Then invert, in tha 

 ease of solid media, and set aside for devel- 

 opment. Fig. 33. Rickards has recently 

 published a modification, which consists in 

 inverting the inoculated tubes, without the 

 plugs, into a glass in which is a layer of dry 

 pyrogallol and then adding the hydroxide. Plate cultures are made 

 by using Erlenmeyer flasks instead of Petri dishes. 



References. A. 206 ; L. & K. 98 ; M. & R. 68 ; M. & W. 117 ; 

 McF. 216 ; P. 233 ; S. 78 ; Wright, Jour. Boston Soe. of Med. Sci., 

 1900, 5, 114 ; Rickards, C. f . B., 1st Abt., Originale, 36 ; 557. 



Fig. 33. Wright's method 

 for cnitivatingr anaerobes. 

 a, cotton plug; 6, alkaline 

 pyrogallic acid solution; c, 

 rubber cork. 



