58 THE VITAMINES 



ing for 45 minutes at 120C. This vitamine could be easily adsorbed 

 by filter paper but not by glass wool. It was shown to be present 

 in blood and in milk (and to a smaller extent in serum). On this 

 basis, a blood agar was prepared (144) which, in spite of the coagula- 

 tion of its protein by heat, still contained vitamine, but could not be 

 subjected to filtration. The precautions to be observed as regards 

 filtration pointed to the probability that they were dealing with two 

 vitamines, both of which were necessary and one of which was either 

 slightly soluble in water or not at all. The latter could be adsorbed 

 by protein, and of special interest, is the fact (145) that the meningo- 

 coccus, after from one to ten re-inoculations, does not need any 

 more vitamine additions, and this is apparently the reason why the 

 importance of vitamines for bacteria was not recognized sooner. At 

 the same time, somewhat similar experiments were carried out by 

 Gordon and Hine (146), and also by Flack (147). These investi- 

 gators were able to show that serum albumin, hemoglobin, fibrinogen, 

 legumin and human blood accelerated the growth of the meningo- 

 coccus on common agar, while the addition of glucose was without 

 any effect. Among others, they recommended trypagar, prepared 

 from pea flour and digested ox heart. The best results were obtained 

 with an agar containing bouillon and an extract of cooked pea flour, 

 or the fractions obtained after removal of starch and dextrin by 

 alcohol. Extracts of raw and cooked wheat embryo showed a 

 similar ability to promote growth and to prolong viability; these 

 authors believed that pea flour contained a vitamine acting on growth, 

 while that from wheat influenced the viability. Shearer (148) also 

 investigated the influence of some extracts. He found the active 

 substance in nasal mucous and believed that it acted not as a usual 

 dietary constituent, but as an activator. The substance was soluble 

 in water, less soluble in alcohol and not at all in ether; it was 

 unaffected by heating with strong hydrochloric acid for 12 hours. 

 Besides the meningococcus, it was active for pneumococcus, B. 

 typhosus, B. coli communis and other pathogenic bacteria. In the 

 continuation of his work, Shearer (149), noted that the cerebrospinal 

 fluid contained a substance which is still more active than blood or 

 nasal mucus. This peculiarity explained the rapid growth of the 

 meningococcus in the brain tissues and in the membranes and 

 cavities of the central nervous system. In this case too, the action 

 was observed not upon the meningococcus only, but also upon other 



