70 LABOBATOKY BACTERIOLOGY. 



4. Boil vigorously for five minutes or until the sediment 

 becomes flaky. 



5. Make up with water any loss by evaporation. 



6. Filter hot through folded filter paper. 



7. Sterilize in the autoclave at 15 lbs. pressure for ten 

 minutes. 



II. Bouillon Agar. 



1. Make a paste of 20 gms. of powdered agar in cold water 

 and add to 1,000 cc. of bouillon. 



2. Boil until dissolved. 



3. Filter through absorbent cotton. 



4. Fill into test tubes taking care not to allow the me- 

 dium to touch the necks of the tubes as this will cause the 

 cotton to stick to the glass when the plugs are removed. 



5. Sterilize in the autoclave at 15 lbs. pressure for ten 

 minutes. 



III. Gelatin. 



1. Dissolve 10 gms. of gelatin in 100 cc. of bouillon (boil- 

 ing hot). Do not boil after the gelatin has been added or 

 the solidifying power may be destroyed. 



2. Filter through filter paper. 



3. Sterilize in the autoclave at 10 lbs. pressure for ten 

 minutes. 



