64 PHYSIOLOaY AND NATIONAL NEEDS 



animals exhibit very different degrees of suscep- 

 tibility to the disease. This can be judged in 

 various ways. Thus it has been found that on a 

 diet deprived as far as possible of the antiscorbutic . 

 factor guinea-pigs develop marked symptoms of 

 scurvy in 14-21 days, and die in 28-30 days, whereas 

 monkeys only develop the characteristic symptoms 

 in about 6-10 weeks, and human beings in as 

 many months. 



Results of the same general character are ob- 

 tained by ascertaining the minimum dose of an 

 antiscorbutic substance which will preserve the 

 animal from scurvy. Thus Miss Chick and her 

 colleagues have found ^ that on the average a 

 guinea-pig of 250 g. weight is protected from scurvy 

 by the daily administration of 1*5-2*5 cc. of fresh 

 lemon juice, and that a monkey weighing about 

 2000 g. is protected by practically the same amount 

 of lemon juice (2*5 cc). Similar results have been 

 obtained by Harden and Zilva (impublished), who 

 have kept a monkey for a whole year without any 

 development of scurvy by the addition of 2 cc. of 

 orange juice to a diet strictly deprived of anti- 

 scorbutic factors, whereas the addition of 1*5 cc. 

 proved insufficient. The minimum dose of orange 

 juice which will preserve a guinea-pig from scurvy 

 is also about 1-2 cc. We may therefore conclude 

 that the monkey is much less susceptible to scurvy 



» Lancet, 1918, Nov. 30. 



