■86 



The culture medium employed was a neutral 1 per cent, meat extract, agar 

 agar, with the addition of varying quantities of grape-sugar, 1, 5 aud 10 per cent., 

 respectively. 



The agar was prepared in an autoclave after the method of v. Meyer & Buchner 

 and every care taken in each preparation to obtain as uniform a material as 

 possible. 



To control the uniformity of the various preparations, estimations were made 

 from time to time of the solids (105° C. ) in the nutrient media, for example: 

 10 cc. 1 % grape-sugar agar = 0.1^69 grm. Residue. 

 10 cc. " " " =0.383 " 



10 cc. " " " =0.374 " " 



To grow the organisms agar agar plates were inoculated with a fresh bouillon 

 culture, by means of a roll of thin platinum foil and within a moist chamber 

 placed in the thermostat at 37. °5 C. 



At the expiration of 48 hours the purity of the culture was controlled and 

 the bacteria-mass carefully removed with a scalpel and dried in a vacuum over 

 sulphuric acid. 



Dr. F. Smith (1) maintains that the presence of grape-sugar in the culture 

 medium causes an increased production of gas and acids. 



However, when the drying operation was conducted in the apparatus of Arz- 

 berger & Zulkowsky, connected with a condenser, the presence of acid in the dis- 

 tillate could not be demonstrated. 



The gas production varied, as the amount of sugar, and the odor of ethylic 

 alcohol was always present, but the odor of the fatty acids was never encountered. 



That volatile acids are formed during the growth of the cultures, under the 

 conditions given, could not be demonstrated. 



The material dried finally at 105° C. was subjected to analysis. 



Estimation of ash : 



" " Nitrogen (Kjeldahl NX6.25=nitrogenous substances. 



" " Ether extract (Suxhelet's app., 48 hours. ) 



" " Alcohol extract (Soxhelet's app., 90 hours.) 



(1) Dr. F. Smith— "Bedeutung des Zucker3. in Kultur Medien." Centralblatt fiir Bact. 

 «. PariitlS, 1-s.l. 



