18 LyVBOfiATOEY BACTERIOLOGTf . 



EXERCISE XII. 



THE AM:\l()NiriCATION OF DRIED BLOOD BY PUKE CULTURES 

 OF SOIL ORGANISMS. 



1. AYeigh off twelve 100 gram portions of sieved, air-dry 

 soil; add to each 5 grams of dried blood; stir thoroughly. 



"3. Transfer to Erlenmyer flasks; increase water to opti- 

 mum content, using 12 cc. additional for the dried blood; 

 plug ; sterilize in autoclave ; cool. 



3. Inoculate as follows, using 1 cc. of vigorous cultures 

 ?-3 days old : 



1 & 2 — B. mycoides. 

 .3 & 4 — B. subtilis. 

 •J & 6 — B. coli. 



7 & 8 — B. pinatus or some other member of the coli group. 

 9 & 10— B. proteus. 

 11 & 12 — Another member of the proteus group. 



4. Incubate for 7-8 days at 20° C. 



5. Transfer to copper flasks, di 

 ammonia formed, in the usual way. 



5. Transfer to copper flasks, distil, and determine the 



