152 THE VITAMINS 



scurvy than man. "This does not indicate that the guinea pig is an 

 unsuitable experimental animal, any more than the fact that the pigeon 

 is more susceptible to polyneuritis than man indicates that it is un- 

 suited to investigations of beriberi." 



In the study of vitamin problems through the evidence obtainable 

 from observations upon disease, two points which are not always clearly 

 distinguished should be kept carefully in mind. From the standpoint 

 of pathology and, to a less extent, of prevention it is of course of great 

 importance that the experimental disease induced in a laboratory animal 

 shall really be the counterpart of the pathological condition observed 

 in man. At the same time it must not be forgotten that the clinical 

 picture tends to grow with the literature of the disease and that the 

 complete clinical picture may easily include symptoms arising from 

 concurrent infections or other causes aside from the deficiency of the 

 vitamin, whereas in laboratory experimentation it is usually sought to 

 study only one variable factor at a time. Thus, in experimental scurvy, we 

 may have a picture not showing all of the features which have sometimes 

 been considered as belonging to typical cases of scurvy in man, yet 

 partly for this very reason the experimental form of the disease may 

 be better adapted to the study of the vitamin problem than is its clinical 

 form. 



Another important factor in the study of scurvy as a deficiency 

 disease through both experimental and clinical evidence is the possi- 

 bility that the disease may exist in a latent or sub-acute or partially 

 developed form in which case the patient does not show the complete 

 or typical clinical picture yet may be demonstrably improved by the 

 same measures which are clearly shown to prevent or cure the disease 

 in experimental animals. This is strikingly true in Hess's experience 

 with infantile scurvy. Hess and Fish (1914) described outbreaks of 

 scurvy occurring in an orphan asylum among children who had been 

 fed with milk heated at 165° F. for 20 minutes or at 145° F. for 30 

 minutes. No orange juice or other antiscorbutic had been fed. These 

 cases in general did not present a fully developed or clear picture of 

 scurvy but represented only an early stage or a partially developed 

 or subacute form of the disease which was, however, responsible for 

 much restlessness, irritability, evident discomfort, and retardation in 

 the growth and development of the children. The condition was cured 

 by the addition of small amounts of orange juice, which, it seems cer- 

 tain, must have been effective because of its antiscorbutic property. 

 Cures were also effected, but less rapidly, by the substitution of raw 

 for pasteurized milk. Modification of the pasteurized milk by the use 



