Isolation 



7 2 3 



relationship of massive development and glycerin was made 

 by Kimla, Poupe, and Vesley,* who found that the most lux- 

 uriant growth occurred when the culture-media contained 

 from 5 to 7 per cent, of glycerin. 



Dogs' Blood-serum. A very successful method of isolating 

 the tubercle bacillus has been published by 

 Smith, f A dog is bled from the femoral ar- 

 tery, the blood being caught in a sterile flask, 

 where it is allowed to coagulate. The serum 

 is removed with a sterile pipet, placed in 

 sterile tubes, and coagulated at 75 to 76 C. 

 Reichel has found it advantageous to add 

 to each 100 c.c. of the dogs' serum 25 c.c. 

 of a mixture of glycerin i part and distilled 

 water 4 parts. The whole is then carefully 

 shaken without making a froth, and dis- 

 pensed in tubes, 10 c.c. to a tube. The 

 coagulation and sterilization he effects by 

 once heating to 90 C. for three to five 

 hours. At the Henry Phipps Institute in 

 Philadelphia I employed this medium with 

 thorough satisfaction for the isolation of 

 many different tubercle bacilli. Smith pre- 

 fers to use a test-tube with a ground cap, 

 having a small tubular aperture at the end, 

 instead of the ordinary test-tube with the 

 cotton-plug. The purpose of the ground 

 glass cap is to prevent the contents of the 

 tube from drying during the necessarily long 

 period of incubation; that of the tubula- 

 ture, to permit the air in the tubes to enter 

 and exit during the contraction and expan- 

 sion resulting from the heating incidental 

 to sterilization. 



To the same end the ventilators of the 

 incubator are closed, and a large evapo- 

 rating dish filled with water is stood inside, 

 so that the atmosphere may be constantly 

 saturated with moisture 



Egg Media. DorsetJ recommends the isolation of the 



* "Revue de la Tuberculose," 1898, vi, p. 25. 



t " Transactions of the Association of American Physicians," 1898, 

 vol. xm, p. 417. 



I "American Medicine," 1902, vol. in, p. 555. 



Fig. 240. Glass 

 capped culture- 

 tube used by 

 Theobald Smith 

 for the isolation 

 of the tubercle 

 bacillus. 



