In order to obtain information regarding the relative amount of vitamin B contained in various plant tissues, Osborne and Mendel52 fed rats upon a vitamin-free basal ration to which was added a weighed quantity of a dried preparation (1 gm.) of the material under investigation. The animals were normal in health and development at the beginning of the experiment and observations were made as to whether the diet received was sufficient to maintain them satisfactorily and induce normal growth. As the daily allowance of B was fixed, while the food intake varied with the individual and still more with the character of the plant product fed, the ratio of the latter to the total food eaten varied in general from 10 per cent of the food or less in the case of those growing best to 15 per cent in the case of those growing most poorly.

52 Oiborne and Mendel, J. Biol. Chem. 30, 29, 1919; lb. 41, 451, 1920.

Alfalfa and clover surpassed all the other vegetable products tested in equal doses, 1 gm. daily as the sole source of B being much more efficient than as much as 16 c. c. of milk per day when given in addition to the same basal ration. Several animals gained 175 gm. in eight weeks on this allowance, a growth equal to the best observed in their stock colony. Timothy hay gave good growth at first, but loss of weight resulted after two or three weeks. Hay made from immature clover, timothy or alfalfa contains much more vitamin than does that from the mature plants, which suggests a possible advantage in substituting hay made from less mature plants than ordinarily used. Tomato is rich in the water-soluble vitamin, 1 gm. daily promoting good growth when the animals would eat that amount; even 02 gm. occasionally promoted limited growth, or at least maintenance. Spinach, cabbage, turnip and carrot were not unlike in their effect as a source of B, 1 gm. doses being no more efficient than 0.5 gm. of alfalfa and clover.

In an earlier paper the same investigators 53 reported that 10 per cent of dried spinach supplies somewhat less than enough of the water-soluble vitamin needed for normal growth; it is about one-quarter as efficient as dried yeast in this respect and twice as efficient as whole wheat, soy beans, dried eggs or milk solids. Fifteen per cent of dried cabbage affords somewhat less than the minimum of water-soluble vitamin needed for normal growth and is thus somewhat less efficient than spinach. Beet root did not equal the other roots tested. The potato is as rich in the water-soluble vitamin as some of the roots tested but even 2 g. of peeled potato did not promote growth at the normal rate during the entire eight weeks period. Dried potato peel is no richer in vitamin content than equal amounts of whole potato. There is no noteworthy difference between new and old potatoes as regards water-soluble vitamin content.

The bulb of the onion also contains considerable quantities of B. The variability in content of B shown by tissues of the same type is demonstrated by the observations of Steenbock and Gross54 that sufficient of B to permit growth was furnished by 15 per cent of carrot, dasheen, or rutabaga, and by a somewhat larger quantity of sweet potatoes, but even 25 per cent of the ration in the form of sugar beet or mangel gave no evidence of furnishing this factor.

53 Osborne and Mendel, J. Biol. Chem. 37, 187, 1919. 54 Steenbock and Gross, J. Biol. Chem. 40, 501, 1919.

Fruits may serve to provide a certain amount of B, though they cannot be regarded as rich in this factor. Oranges, lemons, grapefruit, and prunes are richer, grape-juice, apples and pears poorer in this respect.55 The banana appears to be almost, if not entirely deficient in B.56

Of the various animal products eggs are quite satisfactory both for growth and for protection against polyneuritis. Milk is not a good source of B, although different milks may vary, probably vary considerably, according to the proportion of B present in the diets of the lactating animals.57 Beef muscle contains a comparatively small quantity of B, which is readily extracted from it by water. Liver tissue was found to be much richer, as were also the proteins of heart, kidney, and brain tissue,58 and the pancreatic gland.59 Swoboda,60 who used the yeast test (see p. 35), reports that B is present in large quantities in most of the organs of internal secretion which are of developmental importance, but that tissues high in nuclear material, such as thymus and lymph gland, are low in vitamin content. Fish muscle has no appreciable amount of B61

The accompanying table, showing the comparative relation between certain foodstuffs with regard to their content of antineuritic factor, was compiled by the Medical Research Committee (London) and is based upon the observations of Chick and Hume and of Cooper.62 Wheat germ was taken as a standard and rated at 100.

55 Osborne and Mendel, J. Biol. Chem. 42, 405, 1020.

56Suffuira and Benedict, Ib. ,36, 171, 1918; Loeb and Northrop, lb. 27, 309,1916; Northrop, lb. 80,181,1917.

57McCollum, Simmonds and Pits, J. Biol. Chem. 26, 35, 1916. See also Osborne and Mendel, J. Biol. Chem. 41, 515, 1920.

58Mendel and Osborne, Proc. Soc. Exp. Biol. Med. 15, 71, 1918; J. Biol. Chem. 32, 309, 1917; Ibid. 34, 17, 1918.

59Eddy, J. Biol. Chem. 27, 113, 1916.

60Swoboda, J. Biol. Chem. 44, 531, 1920.

61Drummond, J. Physiol. 52, 103, 1919.

62 Cooper, 8p. Rept. 38, Med. Res. Com.

The value of fresh fruits and vegetables as antiscorbutics was known long before the r61e of the vitamins or even the existence of such factors was recognized. Lind in a treatise on scurvy published in London in the middle of the Eighteenth Century records the remarkable efficacy of orange and lemon juice in the treatment of this disease, and these fruits are still ranked among the most powerful antiscorbutics. Next to oranges and lemons he esteemed cider. Davis 63 has investigated commercial pasteurized cider and finds it of some value although low in antiscorbutic content. Fresh lime juice seems to contain only about one-quarter as much C as lemon juicfe, and preserved lime juice none at all.64 The popular impression that lime juice is potent in the prevention or cure of scurvy is due to a misapprehension, the "lime juice" which earned this reputation having been in fact lemon juice. When the juice of the lime was substituted for this so-called " lime juice " in the stores issued to the navy cases of scurvy became frequent.

Grape juice is said to be about one-tenth as efficient as orange juice 65 and banana is effective if taken in rather large amount,66 but prunes seem to have no antiscorbutic power.67 Tomatoes are most efficient sources of C. Hess 68 recommends them as even more serviceable than orange juice in infant feeding. The distribution of C in fruits seems therefore to be most unequal.