CULTIVATION OF ANAEROBES. 59 



rubber stopper, is very convenient. A good rubber-band fruit jar is 

 satisfactory. A desiccator may be used for plates. An excellent 

 method for anaerobic plates, either in a desiccator with the pyrogallic 

 acid and caustic soda, or less satisfactorily in the open air, is to 

 sterilize the parts of the Petri dish inverted; that is, the smaller part is 

 put bottom downward in the inverted cover (as one would set one 

 tumbler in another). Then, in using, unwrap the Petri dish, lift up the 

 inner part, pour in the inoculated medium into the upturned cover. 

 Then immediately press down the inner dish, spreading out a thin 

 film of medium between the two bottoms. 



J. H. Wright's Method. Make a deep stab culture in glucose agar 

 or gelatin, preferably boiling the media before inoculating. Then 

 flame the cotton plug and press it down into the tube so that the top 

 lies about three-fourths of an inch below the mouth of the test-tube. 

 Next fill in about one-fourth of an inch with pyrogallic acid; then add 

 2 or 3 c.c. of a 10% solution of caustic soda, and quickly insert a 

 rubber stopper. This method is one of the most convenient and 

 practical, and is to be strongly recommended. 



Method of Vignal. In this a section of glass tubing (1/4 in.) is 

 drawn out at either end, as in making a bacteriological pipette, with a 

 mouth-piece containing a cotton plug. The liquid agar or gelatin is 

 then inoculated and the medium drawn up into the tube. In a very 

 small flame the capillary narrowings are sealed off, and we have 

 inside the tube very satisfactory anaerobic conditions. To get at the 

 colonies, file a place on the tube and break at this point.* 



B. (Edematis Maligni (Pasteur, 1877). This is the vibrion 

 septique of Pasteur. It is found in garden soil and in street sweepings. 

 It is the cause of an acute cellular necrosis attended with serous san- 

 guinolent exudation and with more or less emphysema. The organ- 

 ism only becomes generalized in the blood about the time of death and 

 postmortem. Therefore, it is not a septicaemia, as is anthrax. The 

 bacillus is an organism about the size of anthrax (7// by .8), but is 

 narrower and does not have the same square cut or dimpled ends. 



* To obtain material for examination and isolation in pure culture from the deep 

 agar stab-tube, it is best to loosen the medium at the sides of the tube with a heated 

 platinum spud or a flattened copper wire. Then shake the mass out into a sterile 

 Petri dish. It is dangerous to break the tubes with a hammer as some do. 



