Feb. 9, 1924 
The Association of Manganese with Vitamins 
4 2 3 
yolks were dried to a constant weight at 1 io° C., ashed, and the manganese 
determined in each. The yolks contained 2.72 parts per million of 
manganese in the moisture-free material, and the whites did not contain a 
trace of manganese. This fact illustrates the association of manganese with 
the vitamins and further supports the idea that a compound of manganese 
is perhaps the vital factor in the yolk of the egg from the standpoint of 
foods, and also a necessary factor in the development of the embryo con¬ 
tained in the egg. 
MANGANESE IN TOMATOES 
It has been found that tomatoes are rich in vitamins. Four hundred 
grams of ripe tomatoes were dried to a constant weight at no° C., ashed, 
and the manganese determined. In the moisture-free material 12.6 
parts of manganese per million were found, corresponding to 0.62 parts 
per million in the tomatoes used. From the standpoint of manganese 
content, ripe tomatoes should have a vitamin potency three times as 
great as that of raw milk, which is in harmony with the results obtained 
with fresh tomato juice, namely, that it has a high potency as a source 
of vitamins. 
MANGANESE IN ORANGES AND LEMONS 
It has been shown that the juice of oranges and lemons contains the 
antiscorbutic vitamin. Cooper (2) has shown that the peel of oranges 
and lemons also contains the *■ ^-soluble vitamin, and Osborne and 
Mendel (8) have demonstrated *iie presence of water-soluble B in the 
juice of oranges. 
Oranges and lemons were examined for their manganese content. The 
juice from 6 oranges and 12 lemons was filtered separately through 
cheese cloth and dried to a constant weight at no° C., ashed, and the 
manganese determined. The peelings were also dried at no° C., ashed, 
and the manganese determined. The results obtained for manganese, in 
parts per million of the moisture-free material, are as follows: 
Orange. Lemon. 
Juice.* 1.41 3-38 
Peel. 3.20 * 4.12 
From the foregoing results it appears that the lemon contains more 
manganese in its juice and peel than the orange. However, most inves¬ 
tigators assign equal values to each as a source of the antiscorbutic 
vitamin. The parallelism existing between manganese and vitamins 
occurs in oranges and lemons. 
SUMMARY 
Small amounts of manganese are widely distributed in nature, and it 
undoubtedly performs important catalytic functions in plant and animal 
metabolism. The author has obtained data which show conclusively 
that manganese is an essential element in plant economy and performs 
an important function, perhaps catalytic, in the synthesis of chlorophyll. 
The pericarp and germ of rice, barley, and wheat contain considerable 
manganese, but the greater part of this element is removed in the pol¬ 
ishing and milling processes when these cereals are prepared as highly 
milled products for food. The value of manganese in the diet has re¬ 
ceived little consideration heretofore. It is quite logical to assume that 
manganese is in some way connected with the vital factor removed in 
highly milled rice, barley, and wheat. 
