304 



GENEKAL MICROBIOLOGY 



bouillon in each of two 500 c.c. Erlenmeyer flasks and 

 sterilize for twenty minutes each day for three consecu- 

 tive days. 



R2. From a culture of the tuber- 

 cle bacterium furnished, inoculate 

 each flask of veal broth. In mak- 

 ing the inoculations care should 

 be taken to place the inoculum on 

 the surface and to avoid agitation 

 after inoculation. Seal the flasks 

 with paraffin and place in the incu- 

 bator at a temperature of 37 C. 



3. Allow the cultures to grow 

 four weeks after the surface is 

 covered, then shake well, place in 

 a steam sterilizer and subject to 

 steam for two and a half hours. 



4. Filter through a filter paper 

 to remove most of the bacterial 

 growth. 



5. Evaporate to one-tenth its 

 original volume over a water bath 

 at a temperature of 60 C. 



6. To one volume of the con- 

 centrated tuberculin add seven 

 volumes of sterile physiological 

 salt solution containing 0.5% 

 phenol or tricresol and then filter 

 through a Berkefeld filter. 



7. Place the product in 20 c.c. 

 homeopathic vials and seal with wax. Label the vials and 

 place in a cool dark room. 



FIG. 66. Bact. tuberculosis 

 (avian), on Banana. 

 (Orig. Himmelberger.) 



