NUTRITION 233 



inorganic salts. They occur in the outer layers of cereal 

 grains, such as wheat, rice, oats, etc. ; they are also present 

 in most fresh vegetables and, in smaller quantities, in meats, 

 eggs, and milk; and they are produced by the yeast plant 

 during its active growth. Hence they may be extracted from 

 yeast cakes. To them the general name of vitamines has 

 been given. 



In many Eastern countries, where rice forms the chief 

 article of diet, a severe disease known as beriberi is more 

 or less common. It is characterized by grave disorders of 

 nutrition, and in severe forms the nerve fibers undergo 

 degeneration, so that paralysis of the skeletal muscles 

 develops. It was found that beriberi occurred chiefly among 

 those who used polished rice, that is, rice from which the 

 dark outer portion of the grain had been removed in the 

 process of milling, in order to give a whiter rice grain,; 

 it seldom developed in those using the whole rice grain 

 (that is, the unpolished rice). It was furthermore found 

 that from the rice polishings something could be extracted 

 which when administered in very small quantities would 

 cure the disease. Finally, it was found that a similar disease 

 (polyneuritis) could easily be induced in fowls by feeding 

 them on a diet consisting solely of polished rice, but that 

 it did not develop when the extract of rice polishings was 

 administered to the fowls even though their food other- 

 wise consisted wholly of polished rice. This extract would, 

 moreover, cure the disease when it had once developed. 



Whether one group or more than one group of compounds 

 is concerned here is not known. It is clear, however, that 

 we have in the above facts proof of some essential constitu- 

 ent or constituents of the diet other than the usual nutrients. 

 These vitamines seem to occur abundantly in most fresh 

 fruits and freshly cooked vegetables and in the outer por- 

 tion of most cereal grains. They are destroyed by very high 

 temperatures, especially those used in sterilizing canned 



