i6 



required to carry out the directions for the fall term will be 

 furnished. 



n. The preparation of bouillon. Take 500 grams of 

 lean beef, remove all fat, and grind it in a sausage machine 

 or have it minced at the butcher shop. Place the minced 

 meat in an agate iron dish and add 1000 c. c. of distilled or 

 boiled water, (2 c. c. for each gram of meat) and thoroughly 

 stir with a glass rod. Then macerate it with frequent stir- 

 ring in a water bath at a temperature of 65 C. for i hour 

 after the temperature of the meat and water reaches that of 

 the water outside. Remove the meat by straining the liquid 

 through a piece of cheese cloth. For this a meat press is de- 

 sirable. The liquid should equal in quantity the amount of 

 water used, if it does not, add distilled or boiling water to 

 make it up to that amount. To this meat infusion add % 

 per cent, peptone ( Witte's ) and ^ per cent, sodium chlor- 

 ide. Add enough of a i % solution of sodium hydrate to 

 give the liquid a faintly alkaline reaction. In this work the 

 alkalinity can be determined by the use of sensitive litmus 

 paper. (For neutralizing culture media for special or re- 

 search work, see Jour. Am. Pub. H. A., Jan. 1898, p. 73.) 

 The infusion is then boiled in a water bath for ^ of an hour, 

 and allowed to cool. When cool filter it through ordi- 

 nary filter paper. The filtrate should be perfectly clear. 

 The color will vary according to the amount of blood pig- 

 ment in the meat used. After filtering, distribute the bouil- 

 lon in tubes and flasks. See above. Stand the tubes con- 

 taining the bouillon in a wire basket for sterilization. Ster- 

 ilize them by boiling in a closed water bath or steaming in 

 the Arnold's steam sterilizer for 30 minutes,* the time to be 



* The customary method of sterilizing culture media is to steam or 

 boil it for about 10 minutes on each of three consecutive days. This 

 was found very troublesome by the students and feeling that it was 

 not necessary a long series of test experiments were made by Mr. R. 

 C. Reed, who found that one boiling or steaming for 30 minutes gave 



