M uk iG vnisms "i .M.\i'i,i;' Sap 515 



Series A. Glycerin. — As would be expected, growth devel- 

 oped in the control tubes of series A where glycerin was employed 

 as a source of energy, since they were not nitrogen free. Growth 

 became apparent the third day, but was slight and transient. The 

 tubes containing- potassium nitrate appeared exactly like the con- 

 trols. The asparagin tubes developed growth in six days which 

 increased, becoming- very pronounced in two weeks. At no 

 time did development occur in tubes containing urea or ammonium 

 chloric!. 



Series B. Mannit. — No growth occurred in the controls or 

 in tubes containing potassium nitrate. Very feeble growth was 

 observed with ammonium chlorid and with urea. The asparagin 

 tubes showed growth the sixth day which became very pro 

 nounced. A dee]) milky color appeared, and a thick, tough, pel 

 liclc formation and heavy sediment developed. 



Series C. Dextrose. — The controls gave no growth. Potas- 

 sium nitrate, ammonium chlorid and urea all developed feeble 

 growth, which was less transient in the case of ammonium chlorid 

 than with potassium nitrate. Asparagin again gave a luxuriant 

 growth after a period of delay. The development upon asparagin 

 was better when dextrose was used than when either glycerin or 

 mannit was employed. Moreover the organism seemed to be 

 able to make slight development upon potassium nitrate in as 

 ciation with dextrose but not when mannit was substituted, and 

 apparently not when glycerin was substituted. Urea and ammo 

 nium chlorid supported feeble growth with mannit and dextrose 

 but rtot with urea. The results are summarized in the following 

 table in which the sign — denotes no growth, + feeble growth. 

 "J: abundant growth after delay, and ? transient growth probably 

 attributable to nitrogen derived from the glycerin. 



TABLE 47. GEOWTH OX NITBOGENOl S MEDIA 



