NUTRIENT CULTURE-MEDIA 77 



2^ c.c. yV normal sodium hydroxid solution, and finally i per 

 cent, potassium iodid. 



Endo Medium (Fuchsin-Lactose-Agar). To 1000 c.c. 

 agar add lactose, 10 grams; fuchsin (saturated alcoholic 

 solution), 2 c.c.; solution sodium sulphite (10 per cent.), 25 

 c.c.; sterilize in steam, and make acid, o.i per cent. 



Peptone Water (Modified Dunham) (Mother Solution): 



Dry peptone (Witte) 100 parts 



Sodium chlorid 100 



Potassium nitrate i part 



Sodium carbonate i 



Distilled water (95) q. s. ad 1000 parts M. 



When wanted for use, dilute ten times with water. 



Dunham's rosalic acid solution consists of the following: 



Peptone solution (Dunham) 100 c.c. 



2 per cent, solution rosalic acid 0.5 gm. 



Alcohol (80 per cent.) 100 c.c. M. 



To detect acids and alkalis. 



Dieudonne's Medium: 



A. Normal solution potassium hydrate, defibrinated ox- 

 blood, equal parts. Mix, sterilize in autoclave. 



B. Nutrient agar (neutral). Mix 3 parts A with 7 parts 

 B, and pour into Petri dishes; allow to stand forty-eight 

 hours at room temperature before using. 



Milk Culture-medium. The milk used should be fresh 

 and should be placed on ice for eight to ten hours to allow the 

 cream to rise; the skimmed milk is siphoned off into flasks 

 or tubes and sterilized for three successive days. Litmus is 

 often added, or sterile i per cent, azolitmin solution. 



Fresh Egg Cultures (After Hueppe). The eggs in the 

 shell are carefully cleaned, washed with sublimate, and dried 

 with cotton. 



The inoculation occurs through a very fine opening made 

 in the shell with a hot platinum needle; after inoculation, the 

 opening is covered with a piece of sterilized paper and collo- 

 dion. 



