62 THE VITAMINES 



stroma were negative. Cold extraction of blood corpuscles for 24 

 hours with a physiological salt solution gave only a weakly active 

 extract. If hemolysis is induced with distilled water before the 

 extraction, then the vitamines are found in solution. In this case, 

 contrary to what has been noted previously in this chapter, the 

 extracts may be filtered through a Chamberlain filter or through 

 paper without loss of activity; this characteristic permits of steriliza- 

 tion without the use of heat. Incidentally, the action of vitamines 

 has been erroneously ascribed to their peculiar physical condition. 

 Legroux and Mesnard (165) extended their experiments to include 

 extracts of kidney, liver and heart. Davis (165a) has pointed out 

 the necessity of two substances for the growth of B. influenzae, one 

 derived from the blood pigment and one of a vitamine nature. The 

 same conclusions were reached by Rivers and Poole (165b), by 

 Thjotta (165c) and by Thjotta and Avery (165d). Thjotta and 

 Avery differentiate between a thermo-stable substance contained 

 in blood, and called "A," and a thermo-labile substance "V" (vita- 

 mine) which is found in blood, yeast and vegetable extracts. Crys- 

 talline hemoglobin contains only the substance "A." 



Finally, there are the vitamine studies of Kligler (166) on bacteria. 

 At first he used autolyzed yeast and found that pneumococci and 

 meningococci do not grow so well on it as on bouillon. In a later 

 work, he (167) investigated the influence of ox heart, goat blood, 

 rabbit and cat tissue and human excreta on gonococcus, meningo- 

 coccus, pneumococcus, Streptococcus hemolyticus, B. diphtheriae, B. 

 pertussis and B. influenzae. All of the investigated extracts exerted 

 a favorable action in exact proportion to the amount added. The 

 spleen, liver and kidneys were rich in vitamines, while muscle 

 tissue was only slightly active, and ether extracts were inactive. 

 Mueller (167a) found that streptococcus needed for growth a sub- 

 stance which he regarded as a new amino acid. The streptococcus 

 was cultivated on beef-heart extracts. If this medium was de- 

 colorized with "norit" it was unsuitable for growth, but permitted 

 of growth upon the addition of peptone or certain protein hydrol- 

 yzates. The growth substance was precipitated from these hydrol- 

 yzates with mercuric sulphate, but it was not identical with 

 tryptophane, tyrosine, cystine or histidine. In a subsequent 

 publication the same author (167b) accepted the necessity of three 

 substances for the growth of Streptococcus hemolyticus one which 



