78 LABOEATOEY BACTEEIOLOGY. 



5. Enough of the solution for "nitrite formation" is added 

 to lialf cover the block. 



6. Sterilize in the autoclave at 15 lbs. pressure for 10 

 minutes. 



XXIII. WinogradsMs Mcdiinn for N Urogcn^Fixation. 



1. To IjOOO. cc. distilled water add the following sub- 

 stances : 



1.0 gm. KjHPO,. 

 0.5 gm. MgSO,. 

 0.01 gm. NaCl. 

 0.01 gm. FeASO,),. 

 0.01 gm. MnSOi. 

 20 gms. dextrose. 

 30 gms. CaCOs. 



2. Stir until all the substances except the CaCOj are in 

 solution. 



3. Sterilize in the autoclave as usual. 



XXIV. Winogradski's Agar. 



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

 water and add to 1,000 cc. of the solution XXIII. 



2. Boil until dissolved. 



3. Filter through absorbent cotton. 



4. Sterilize in the autoclave as usual. 



