122 Scientific Proceedings (34). 



clavin, which when purified free from ash had the properties de- 

 scribed by Vahlen, consisted entirely of these three amino acids, 

 the latter being isolated analytically pure : 2.02 grams of clavin 

 gave 0.79 gram of leucin, 0.45 gram isoleucin, 0.75 gram valin. 

 We have not yet determined whether any of these amino acids has 

 the pharmacological effect assigned to clavin. 



66 (404) 



Some effects of sodium benzoate. 

 By DANIEL R. LUCAS. (By invitation.) 



\_From the Laboratory of Biological Chemistry of Colwnbia Uni- 

 versity, at the College of Physicians and Surgeons 7\ 



This research was suggested to me by different experiences 

 with sodium benzoate when taken by mouth in the following ways : 

 A. Pure (i) as crystalline salt, or (2) in aqueous solution. B. 

 In neutral or alkaline solutions, or in mixtures rich in fat, carbo- 

 hydrate or protein, e. g., milk. C. With vegetable or fruit acids (i) 

 hoi", as in tomato soup, or (2) cold, as in canned plums, oranges, 

 lemons, etc. D. In beverages containing high percentages of 

 organic acids, e. g., cider, lemonade, grape juice, wine, etc. E. 

 In mixtures containing inorganic acids, e. g., artificial gastric juice. 



Brunton has studied the effects of benzoic acid on enzymes and 

 bacteria. The strong inhibiting effect of this substance on their ac- 

 tivity is in striking contrast to the slight effect of sodium benzoate. 

 Doepner has shown that fairly large quantities of sodium benzoate 

 (2 per cent.) did not prevent the development of Proteus vulgaris 

 and, in strengths equal to 0.5 per cent., only slightly retarded the 

 development of B. enteritidis, B. fluorcscens and B. coli. Fleck 

 found that benzoic acid in concentrations equal to 0.6-0.7 per cent, 

 caused marked inhibition of yeast fermentation and that the inhib- 

 iting action was markedly decreased by the amount of protein 

 present. Lehman observed that meat extract putrefies in the pres- 

 ence of I to 2 per cent, of sodium benzoate, but less benzoic acid 

 acts more strongly antiputrefactive when the reaction of the medium 

 is markedly acid. The action of sodium benzoate under markedly 

 acid conditions is the same as the action of benzoic acid. Under such 

 conditions the action of the benzoate diminishes with decrease of 



