516 



BACTERIOLOGY. 



The contents of each of the capillary tube's are then in- 

 oculated into bouillon which is set aside at 37° to allow the 

 growth, it any, to develop. The contents are removed 

 as follows: The tube is first wiped dry and then one 



end is slightly scratched with 

 a file. The end is then removed 

 and the opening of the tube is 

 sterilized by touching it 2 or 3 

 times to a flame. The tube is 

 held in a broad-pointed pair of 

 forceps, and, when cool, the cut 

 end is inserted into the culture 

 tube while the closed end is 

 slowly brought 'jnto contact with 

 a flame. The vapor thus pro- 

 duced promptly expels the liquid 

 from the capil- 

 lary. 



The student should 

 make suspensions 

 and test one or more 

 of the following' or- 

 ganisms, according 

 to the directions 

 given above, Chol- 

 era vibrio, Typhoid 

 bacillus. Anthrax 

 < bacillus (homogeneous 



cultv/re), Anthrax spores (p. 291) and Streptococcus pyogenes. 



Action of moist heat at 58°. — The capillary tubes should be with- 

 drawn at the. end of 5, 10, 15, 30 and 60 minutes' exposure. 



Action of moist heat at 70°. — The capillary tubes are withdrawn at 

 the end of 1, 3, 5 and 10 minutes. In addition to this the anthrax 

 spore tubes should be exposed for 15, 30 and 60 minutes. 



Fig. 75. Determination of tlie tiiermal death-point {F, G. N.)- 



Action of moist heat at 100°. — The capillary tubes are withdrawn at 

 the end of 1, 2 and 3 minutes. Additional anthrax spore tubes are ex- 

 posed for 5, 10 and 15 minutes. 



