THE REQUISITES OF THE DIET 347 



as vitamins. The list will probably be extended year 

 by year. 



Deficiency Diseases. Long before the conception 

 of vitamins was clearly presented it was known that 

 nutritional disasters sometimes resulted from restricted 

 and peculiar diets. The records of explorers contained 

 many references to scurvy, a distressing disease which 

 prostrated many members of their parties when the 

 food was limited in variety and not fresh. The victims 

 of scurvy became very weak and suffered from intense 

 soreness of the gums, loosening of the teeth, a tendency 

 to hemorrhage, friability of the bones, and other symp- 

 toms. Certain articles, such as lemons, limes, potatoes, 

 and fresh meat, gained the reputation of being anti- 

 scorbutics, that is, of preventing or curing scurvy. 



It was formerly held that the foods causing scurvy 

 had become in some degree poisonous through deteriora- 

 tion during lo.ng keeping. The good effects of the anti- 

 scorbutics were then explained as due to an antidotal 

 action. But we are now inclined to regard scurvy not 

 as a state of poisoning, but as a deficiency disease, the sys- 

 tem being disordered for want of some particular supply. 

 Assuming that one specific substance is lacking we say 

 there is need of a vitamin and we believe that it can be 

 conveyed in the various antiscorbutics. We speak some- 

 what inaccurately of the " vitamin of scurvy," meaning 

 the vitamin in the absence of which scurvy develops. 



Another deficiency disease is beri-beri. This is 

 common in the far East, while a condition very much 

 like it has occasionally been observed in this country. 

 It used to be thought that beri-beri was an infectious 

 disease, and the impression gained strength from the 

 fact that it often raged where men were closely quar- 

 tered, as in prisons and laborers' camps. But these 

 were situations in which the diet was common to all 

 and not of a varied character. Better feeding has 

 always stamped out beri-beri and cured all but the 

 most advanced cases. 



