SPECIAL MEDIA 59 
Redfield’s (1912) Medium. 
Distilled water... 0.0... 000.000. cece eee 1000 c.c 
Peptone... 2... 0... eee eee 300 gms 
Potassium chloride (KCl).......0 ..0....... 74 gms 
Add the peptone to 700 ¢c.c. of hot water. Stir until it is in solution 
and cool. Allow to stand over night in the icebox. Filter and put in 
test tubes. 
Ox-bile Medium. Dissolve ! per cent lactose and 1 per cent pep- 
tone in fresh ox-bile, filter and plage in fermentation tubes. Sterilize 
in an Arnold on three successive days. 
Decoction of Dried Fruits. 1. Macerate 50 to 100 gms. of dried 
fruit in a liter of water for several hours. Then stew them in the 
water. 
2. Pass through a coarse sieve. 
3. Boil. Filter. 
4. Tube and sterilize at 115° C. 
The liquid is slightly acid and is useful for cultivating molds. Other- 
wise make neutrai. 
Barsiekow’s Medium. Prepare and sterilize separately the two 
following solutions: 
A. Sodium chloride, NaCl.................. 0.5 gm. 
Nutrose..... 02.02.0002 cece eee eee 1.0 gm. 
Water 02... ee ccc cee eee 75.0 gms 
B. Water... 22... ccc cece cece ee eee 25.0 gms 
Litmus............. eee ee eee cena To give blue color 
Sugar (the one desirad).................- 1.0 gm. 
Add sufficient litmus to give an amethyst color. After cooling 
mix and distribute in tubes. 
Bread. Soak some slices of white bread in distilled water and 
sterilize at 115° C. 
Crumble some dry bread and allow to dry. Grind when dry and 
put in Petri disher or Erlenmeyer flask and add water to moisten (about 
4 pts. of H2O to 1 pt. of bread by weight). 
Sterilize at 115° C. for twenty minutes. 
