CULTURE-MEDIA. 8l 



tion; subsequently sterilize at 75 C. so as not to coagulate 

 the albumen of the blood-serum. The nutrient agar in this 

 case should contain 2 per cent, of dry agar. Another ex- 

 pedient has also been to smear a little blood over the sur- 

 face of a tube of nutrient agar blood-agar used for culti- 

 vating the bacillus of influenza. Marmorek's blood-serum 

 is supposed to assist in maintaining the very evanescent 

 virulence of the streptococci ; it consists of bouillon mixed 

 with human blood-serum, ass's serum or horse's serum. 



Guarnieris medium consists of a mixture of gelatin and 

 agar. 



Media containing fat were employed by Sommaruga to 

 test the ability of bacteria to decompose fats. Clarified 

 beef-suet or olive-oil in the proportion of I or 2 per cent. 

 is added to gelatin or agar. The fat must be mixed with 

 the melted medium; it is to be shaken and then rapidly 

 cooled in a freezing-mixture after the last sterilization. 



Fresh eggs in their shells may be used without other 

 preparation than washing the surface thoroughly with bi- 

 chloride of mercury solution; or after sterilization by steam, 

 which of course coagulates the albumen. The egg is easily 

 inoculated through a small opening made with a heated 

 needle, which may be closed afterward with collodion. 

 Hueppe recommended eggs closed in this manner for the 

 cultivation of anaerobic bacteria. Egg-albumen has been 

 used as a constituent of various media. Dorset 1 states that 

 good results may be secured when eggs are used as a cul- 

 ture-medium for tubercle bacilli. The yolk and the white 

 are mixed, poured into tubes, slanted, coagulated, and ster- 

 ilized. Just before using pour into the tube a few drops of 

 sterile distilled water to moisten the medium. 



Bread-paste (finely-divided dry bread, mixed with water 

 and sterilized) is used for the cultivation of moulds. Sa- 

 1 American Medicine, April 5, 1902. 



