MANNIT SOLUTION 109 



Medium 40 

 Dextrose Solution 



Dibasic potassium phosphate (K2HPO4) 0.2 gm. 



Dextrose (C6H12O6) lo.o gm. 



Tap-water looo.o c.c. 



For a solid medium add 1.5 per cent, of agar. 



(Anaerobic) 



Medium 41 

 Solution for Anaerobic Organisms 



Dibasic potassium phosphate (K2HPO4) i.o gm. 



Magnesium sulphate (MgSOi + 7H2O) 0.2 gm. 



Sodium chlorid (NaCl) o.oi gm. 



Ferrous sulphate (FeS04 + 7H2O) o.oi gm. 



Manganese sulphate (MnS04 + 4H2O) o.oi gm. 



Dextrose (C6H12O6) • 20.0 gm. 



Calcium carbonate (CaCOs) 30-0 gni. 



Distilled water looo.o c.c. 



Sterilize at 15 pounds' pressure for fifteen minutes; or, bet- 

 ter, steam twenty minutes for three consecutive days. 



Winogradsky, S., Centbl Bakt. (etc.), Abt. 2, Bd. 9, p. 49, 1902. 



B. Symbiotic Nitrogen-fixing Bacteria 



Medium 42 

 Mannit Solution 



Mannit solution same as No, 39 with an excess of cal- 

 cium carbonate removed. 



