274 



PRACTICAL DAIRY BACTERIOLOGY 



removed ready for use and, since they are sterile they will keep 

 indefinitely. They will be called ivater blanks. (Note. The 

 autoclav may be used to sterilize other liquid media. If it is 

 used for gelatin care must be taken not to allow the pressure 



99 c.c. 



19 c.c. 



4c,c. 



FIG. 75 VIALS FOR MILK DILUTION 



to rise above 5 Ibs., or the gelatin will refuse to harden sub- 

 sequently. The successful use of the autoclav for sterilizing 

 gelatin requires considerable experience.) 



b. Shake the milk to be tested, very vigorously, in order to 

 insure uniformity, and, with a sterile pipette remove one c.c. to 

 one of the vials holding 9 c.c. of water. Shake, and with a 

 fresh pipette transfer one c.c. to a second water blank of nine 

 c.c. Shake again, and with a fresh pipette transfer one c.c. 



-f 



