INTRODUCTORY 41 



{89) then showed that from a mixture of autolyzed yeast and orange 

 juice, substances frequently used as a source of both vitamines, 

 vitamine B could be completely removed by adsorption with fuller's 

 earth, while the presence of vitamine C could be demonstrated in the 

 filtrate. These findings have been corroborated by Byfield, Daniels 

 and Loughlin (90) incidental to some other work. Vitamine C is the 

 most unstable of the vitamines, although it appears to be more 

 stable in juices that are slightly acid. In association with these 

 facts, there is the discovery of Fiirst (91), who was the first one to 

 show that if grains are allowed to germinate a formation of vitamine 

 C takes place, which disappears again upon drying and reappears 

 upon the addition of water. We have thought (1. c. 62) that in 

 this observation there was a possibility of finding a genetic relation- 

 ship between vitamine C and vitamine B. Through progress in the 

 methods of demonstrating the presence of vitamine B, it may be 

 possible to investigate the question, if with the formation of vitamine 

 C there is a corresponding diminution in vitamine B. The relation- 

 ship between these vitamines has become more interesting, since 

 Osborne and Mendel (92) showed that known antiscorbutics, such 

 as fruits, always contain a definite amount of vitamine B. Although 

 we know that this vitamine has no effect upon scurvy, the reverse of 

 this, the influence of vitamine C on beriberi, is not sufficiently estab- 

 lished. It might be possible for instance, that for the cure of scurvy 

 very small amounts of vitamine C are necessary, whereas to in- 

 fluence beriberi similarly much larger doses are required. This 

 matter must be cleared up by further research. 



We must also put forth the question whether, with the enumeration 

 of the above three vitamines, we have exhausted all the possibilities. 

 There is no definitive answer to this at present, but it is frequently 

 touched upon in the latest investigations, and it came into prominence 

 through a review of the available data by Mitchell (93), pointing to 

 the idea that vitamine B is different from the growth-promoting 

 substance. In spite of this, we must note that the conclusions of 

 Mitchell are not indisputable. He compared earlier work done with 

 comparatively inefficient methods, with newer work that is more 

 liable to be accurate, and consequently it is not to be wondered at 

 that he found a difference; besides, he compared extracts made from 

 different materials. Somewhat later, there appeared the first experi- 

 ment on this matter of Emmett and Luros (94), which at least had 



