SOLUTION FOR YEASTS 119 



Medium 64 

 Agar for Isolating Iron-precipitating Bacteria 



Ferrous ammonium citrate (about i6 per cent. Fe) 0.5 gm. 

 Heyden-Nahrstoff agar (see page 93) looo.o c.c. 



Medium 65 



Solution for Testing the Effect of Bacteria on Insoluble 



Phosphates 



Asparagin (C4H8N2O3 + H2O) 5.0 gm. 



Sodium chlorid (NaCl) i.o gm. 



Potassium sulphate (K2SO4) 1,0 gm. 



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



Bone-meal 4.0 gm. 



Distilled water 1000,0 c.c. 



The bone-meal should be passed through a fine sieve and 

 thoroughly washed. In order to secure the largest amount 

 of soluble phosphoric acid the cultures should be incubated 

 for sixty to ninety days. 



Sackett, Patton and Brown, Bui. 43, Mich. Agr. Exp. Sta., 1908. 



YEASTS 



Medium 66 

 Solution for Yeasts 



Dibasic potassium phosphate (K2HPO4) 0.75 gm. 



Ammonium sulphate ((NH4)2S04) S-o gm. 



Magnesium sulphate (MgS04 + 7H2O) o.io gm. 



Tartaric acid (C4H6O6) i.o gm. 



Dextrose (CeHwOe) loo-o gm. 



Distilled water looo.o c.c. 



