7? LABOEATOEY BACTERIOLOGY. 



VI. "Mannitc" Agar. 



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

 add to 1,000 cc. of "mannite" solution. 



2. Boil until dissolved. 



3. Filter through absorbent cotton. 



4. Sterilize in the autoclave as usual. 



VII. "Giltay" Solution for Denitrification. 



1. Dissolve the following substances in 800 cc. of distilled 

 water: (Solution I.) 



2 gms. KHi,PO,. 

 2 gms. MgSOj. 



1 gm. KNO,. 

 0.2 gm. CaClj. 



2 drops sol. FejClc. 

 5 gms. citric acid. 



2. Add a few drops of phenolphthalein and then by means 

 of a pipette drop in just enough 10% NaOH to turn the 

 solution a faint pink color. 



3. Dissolve 10 gms. dextrose in 200 cc. of distilled water 

 (Solution II). 



4. Mix solutions I. and II. very thoroughly. 



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

 minutes. 



