VITAMIN C 197 



Pierson and Butcher (1920). Scheunert (1929) considers it to be 

 a good source of vitamin C in the raw state but to lose more than 

 half of its antiscorbutic properties when heated with equal parts of 

 water and sugar and sealed. Other stem vegetables tested by Scheunert 

 include kohlrabi reported to be a good source, and asparagus a very 

 good source of vitamin C when tested raw. Two grams daily of raw 

 asparagus afforded complete protection against scurvy but cooked 

 asparagus was of little value. 



Onions are reported good antiscorbutics by the British Committee. 

 See also Shorten and Roy (1919, 1921). 



Leaves are apparently good antiscorbutics, particularly if they can 

 be eaten raw, but until quite recently only a few of them have been 

 studied. Lind gave directions for the use of fir tops as an antiscor- 

 butic in time of need, and referred to "scurvy grass," cress, and spinach 

 as foods of known antiscorbutic value. Hoist and Frolich (1912), as 

 noted previously, demonstrated antiscorbutic properties in cabbage, 

 dandelion leaves, lettuce, endive and sorrel. 



Cabbage has been more extensively studied than any other leafy 

 vegetable, doubtless because it is quantitatively the most important 

 of this class of vegetables and perhaps in part also because it is so 

 commonly fed to, and so readily eaten by, the guinea pig, which usually 

 serves as the experimental animal in studies of the antiscorbutic 

 vitamin. 



Reference has already been made to the experiments of Hoist and 

 Frolich with raw, cooked, and dried cabbage. The work of Delf (1918) 

 and of Delf and Skelton (1918) indicated that with a good basal 

 diet from 1.5 to 2 grams of raw cabbage will suffice to prevent scurvy 

 in a guinea pig, thus pointing toward as high a concentration of the 

 antiscorbutic vitamin in the raw leaf as in the juice of the orange 

 or lemon and somewhat higher than in the tomato. In practice, how- 

 ever, cabbage is probably a less important antiscorbutic than the tomato, 

 because the cabbage loses a much larger fraction of its vitamin C in 

 cooking than does the tomato. (See, also, the section on chemical 

 behavior beyond.) 



Delf (1918) found that five grams of cabbage cooked for one hour 

 at 60° C. or for twenty minutes at 100° C. was equivalent in anti- 

 scorbutic properties to one gram of raw cabbage. This suggests a 

 rather low temperature coefficient of destruction of the vitamin, since 

 a temperature increase of about 40° C. apparently increased the rate of 

 destruction only about three-fold. In experiments in which cabbage was 

 heated at temperatures of from 100° to 130° C. the destruction of anti- 



