The Absorption of the Atmospheric Oxygen 219 



can contain a number of tubes or Petri dishes at a time. For this 

 purpose the jar invented by Novy or the apparakis of Botkin can 

 be used. 



The Novy jar receives as many inoculated tubes as it will contain 

 and has its stopper so replaced that the openings in the neck and 

 stopper correspond. Hydrogen gas is passed through until the air 

 is displaced. This usually takes several hours, as the cotton stop- 

 pers retain the air in the test-tubes and prevent rapid diffusion. 

 When the air is all displaced, the stopper is turned so that the tubes 

 are closed. If it be desired to expedite matters a pump can be 

 used to withdraw the air, after 

 which the hydrogen is permitted 

 to enter. , 



Botkin's apparatus is intended 

 for cultures in Petri dishes. It 

 consists of three parts — a deep 

 dish of glass (b), a stand to sup- 

 port the Petri dishes to be ex- 

 posed (c), and a bell-glass (a) to 

 cover the stand and fit inside of 

 the dish. The prepared dishes 

 are stood uncovered in the rack, 

 which is then placed in the dish 

 forming the bottom of the ap- 

 paratus, and into which liquid 

 paraffin is poured to a depth of 

 about 2 inches. The bell-glas? 

 cover is now stood in place and 

 hydrogen gas is conducted 

 through previously arranged 

 rubber tubes (d, e). As soon as the air is displaced through tube d, 

 both tubes are withdrawn. It is well to place one Petri dish contain- 

 ing alkahne pyrogaUic acid in the rack to absorb any oxygen not 

 successfully displaced. 



3. The Absorption of the Atmospheric Oxygen. — This method 

 was first suggested by Buchner, whose idea was to absorb the atmos- 

 pheric oxygen by alkaline pjaogallic acid and permit the bacteria 

 to develop in the indifferent nitrogen. Various methods have been 

 suggested for achieving this end," Buchner 's own method consist- 

 ing in the use of two tubes, a small one to contain the culture and a 

 larger one to contain the absorbing fluid. A fresh solution of p3T0- 

 gaUic acid and sodium hydroxid were poured into the large tube, 

 the smaller tube placed within it, upon some appropriate support, 

 and the whole tightly corked. 



Nichols and Schmitter, * at the suggestion of Carroll, have modified 

 the method by connecting the tube containing the inoculated 

 * "Jour, of Medical Research," 1906, xv, p. 113. 



Fig. s8. — Botkin's apparatus for 

 making anaerobic cultures. 



