12 BIOLOGICAL PROBLEMS 



unknown. It is true that the name "vitamines" was 

 introduced by Casimir Funk a few years ago, on the 

 mistaken belief that he had discovered the chemical 

 nature of the factor necessary to prevent beriberi. 

 The chemical implication of the name is misleading, 

 since it has turned out that, so far from these sub- 

 stances being amines, they do not always even contain 

 nitrogen at all. It would be better to avoid the use 

 of the term altogether, but, owing to the fact that no 

 satisfactory short name has been proposed, " vita- 

 mine" has come into rather general use, regrettable 

 as it may be. 



The subject is dealt with in a special lecture of this 

 series, so that very few words will suffice in this place. 



Most natural articles of food contain some of them, 

 although in varying amounts. Fresh fruit and vege- 

 tables are the richest source, especially of the anti- 

 scorbutic factor. They are destroyed by prolonged 

 heating and by certain preservative methods. Alkali 

 makes them more vulnerable. 



They appear to be of several kinds, but may be 

 divided into two main groups, as M'CoIlum has 

 shown. Thus, rats fed on polished rice alone will 

 not grow, nor if butter be added, nor again if wheat 

 germ alone is added. But it is only necessary to add 

 a minute quantity of both together to make polished 

 rice perfectly adequate. The factor in butter is re- 

 presentative of a group soluble in fats, hence called 

 "Fat-soluble A factor". That in wheat germ is one 

 of the group known as " Water-soluble B factor". 



Wheat germ or any dried seed is insufficient to 

 prevent scurvy. The factor develops only on germi- 

 nation, as shown by Dr. Chick and Miss Hume. 



Economy in Diet. I may conclude with a few re- 

 marks on the question that concerns us so vitally at 

 the present time. That care and economy are always 



