212 SPECIAL MEDIA 



Serum Agar (Libman). 



1. Prepare nutrient agar (vide, page 167) using, however, 1.5 

 per cent, peptone (that is 15 grammes per litre instead of 10 

 grammes) . 



2. Adjust the reaction to o (i. e., neutral to phenolphthalein) . 



3. Filter and transfer 1000 c.c. liquefied medium to a sterile 

 flask. 



4. Weigh out dextrose 20 grammes and dissolve in the fluid 

 agar. 



5. Tube in quantities of 6 c.c.; and sterilise in the steamer at 

 100 C. for thirty minutes on each of three consecutive days. 



6. After the third sterilisation cool to 42 C. and add to each 

 tube 3 c.c. of sterile hydrocele fluid, ascitic fluid or pleuritic effu- 

 sion (previously sterilised, if necessary, by the fractional method) ; 

 allow the tubes to solidify in a sloping position. 



7. When solid, incubate at 37 C. for forty-eight hours, and 

 eliminate any contaminated tubes. Store the remainder for 

 future use. 



Egg=albumen, Inspissated. 



1. Break several fresh eggs (hens', ducks', or turkeys' eggs), 

 and collect the "whites" in a graduated cylinder, taking care to 

 avoid admixture with the yolks. 



2. Add 40 per cent, distilled water, and incorporate the 

 mixture thoroughly by the aid of an egg-whisk. 



3. Weigh out 0.15 per cent, sodium hydrate and dissolve it 

 in the fluid (or add the amount of dekanormal caustic soda 

 solution calculated to yield the required percentage of soda in 

 the total bulk of the fluid i. e., 0.375 c>c< f dekanormal NaOH 

 solution per 100 c.c. of the mixture). 



30. Glucose to the extent of i to 2 per cent, may now be added, 

 if desired. 



4. Strain the mixture through butter muslin and filter through 

 a porcelain filter candle into a sterile filter flask. 



5. Tube, and stiffen at 100 C. in the serum inspissator. 



6. Incubate at 37 C. for forty-eight hours and eliminate any 

 contaminated tubes; store the remainder for future use. 



Egg=albumen (Tarchanoff and Kolesnikoff ) . 



1. Place unbroken hens' eggs in dekanormal caustic soda solu- 

 tion for ten days. (After this time the white becomes firm like 

 gelatine.) 



2. Carefully remove the shell and cut the egg into fine slices. 



3. Wash for two hours in running water. 



4. Place the egg slices in a large beaker and sterilise in the 

 steamer at 100 C. for one hour. 



5. Transfer each slice of egg by means of a pair of sterilised 

 forceps to a Petri dish or large capsule. 



