XI. REQUIREMENTS 391 



tivaso the neocl for otlier \itumiiis, increase the need for ii.sc'orl)ic acid also. 

 These are conditions characterized by increased metabolism, l)y increased 

 loss of the vitamin in urine, stool, or vomitus, by decreased absorption, or 

 by increased destruction. 



In 1757, James Lind'^ wrote almost as clearly on the circumstances sur- 

 rounding the genesis of ascori)ic acid deficiency as we can today. Although 

 he was mistaken as to the bad aifects of salt water and salt air, his powers 

 of observation led him to discover the true cause of scurvy and many of 

 the factors influencing its occurrence. He listed the following predisposing 

 factors to scurvy: recovery from other diseases, weakness of the digestive 

 tract, indolence, mental disturbances (as in impressed seamen), and ex- 

 cessive use of distilled spirits, though beer and fermented liquors seemed 

 to have an antiscorbutic effect. Then he wrote 'T come in the next place, 

 to an additional and extremely powerful cause, observed at sea to occasion 

 this disease and which concurring with the former in progress of time seldom 

 fails to breed it. And this is, the want of fresh \'egetables and greens; either 

 as may be supposed, to counteract the bad effects of their before mentioned 

 situation, or rather, and more truly to correct the fjuality of such hard dry 

 food as they are obliged to make use of. Experience indeed sufficiently shows 

 that as greens or fresh vegetables, with ripe fruits, are the best remedies 

 for it, so they prove the most effectual preservatives against it. And the 

 difficulty of obtaining them at sea, together with a long continuance in 

 the moist sea air are the true causes of its so general and fatal malignity 

 upon that element." 



XII. Future Problems 



MARY ELIZABETH REID 



Although there is no field in which fiu'ther investigations on \'itamin C 

 could not be made profitably, problems of special urgency' invoh'e studies 

 on (1) the pathology of scur^^'■, (2) relation of the vitamin to phagocytic 

 activity and fragility, (3) changes in the circulatory system, (4) mineral 

 metabolism, and (5) interrelations with other vitamins. 



a. The Pathology of Scurvy 



^luch of the discrepancy in the reports on the pathology of Wtamin C 

 deficiency is caused by the fact that some investigators studied the acute 

 condition whereas others dealt with the chronic type. There has been a 

 tendency to criticize the chronic studies because of the absence of some of 

 the acute symptoms and the presence of other symptoms not found in 

 the acute disease. It seems clear that studies of both types are necessary. 



'^ J. Lind, Treatise on Scurvy, 2nd ed. A. Millar, London, 1757. 



