50 BIOLOGICAL PROBLEMS 



that guinea-pig scurvy is a condition similar to human 

 scurvy, and is produced and controlled by the same 

 conditions. Acting upon this assumption, all our 

 experimental work on scurvy in connection with war 

 problems has been done on this animal. 



The anti-scorbutic vitamine as far as we have been 

 able to ascertain by experiments on the minimum 

 doses of different food-stuffs, needed to protect guinea- 

 pigs from scurvy is abundantly present in fresh 

 citrus fruits, e.g. oranges and lemons. Fresh lime- 

 juice, however, is disappointing, and commercial clari- 

 fied lime-juice is quite useless. Fresh leaves, such as 

 cabbage leaves, are as rich as oranges and lemons, 

 but roots and stem-tubers, carrots, potatoes, and 

 onions, for instance, contain it less abundantly, 

 though it is appreciably present. Fresh meat and 

 milk contain even less. 



It is not present in ungerminated seeds, but, as was 

 discovered by Fiirst, develops in them immediately 

 on germination, so that peas or lentils, after twenty- 

 four hours' germination have, weight for weight, a 

 value approaching that of fresh cabbage. 



But if fresh fruit juices are squeezed out and kept, 

 or if cabbage leaves or milk are dried and kept, the 

 anti-scorbutic vitamine will gradually suffer loss, and 

 in a few weeks or months, though they may be excel- 

 lent articles of food in all other respects, the vitamine 

 is reduced, and with an exclusive diet of food-stuffs 

 so treated there is undoubted danger of scurvy. 



In addition, the anti-scorbutic vitamine is much less 

 thermo-stable than the anti-beriberi vitamine. At 

 room temperature, as just described, it disappears spon- 

 taneously in a few weeks, or sometimes even days, 

 according to the particular food-stuff. In cold storage 

 it is better preserved, and it may last some months. 



At the higher temperatures, such as that of cooking 



