wth curve of young rats.[12]

230 +----------+----------+
| | |
| | |
| | |
| | |
| | |
190 +----------+---------/+
| | / |
| | / |
| | / |
| | / |
| | / |
150 +----------+---/------+
| | / |
| With | / |
| "Fat |/ |
| Soluble / |
| A" /| |
110 +--------/-+----------+
| / | |
| / | |
| / | |
| / | |
| / | |
70 +--/-------+----------+
| / | |
|/ Without "Fat Soluble A"
|----------|----------|
| | |
| | |
30 +----------+----------+
0 1 2

Figure showing the effect upon growth of adding "fat soluble A"
to a diet adequate in all other respects. Courtesy of Dr. E. V.
McCollum.

Mellanby of England believes the "A" vitamine to be a factor in the
prevention of rickets. Scientists of America have recently
investigated this disease, and Dr. Hess (New York) has found cod
liver oil to be a remedy for it. Cod liver oil is known to be rich in
"Fat soluble A," but whether the cure of rickets is due to the
presence of this vitamine in the oil, or to a possible fourth
vitamine, is still undetermined.

~Effect of Heat on the "A" Vitamine.~--Heat, as applied in the
ordinary methods of cooking, is not believed to exert a great deal of
destruction upon the "A" type of vitamine; but hydrogenation, the
process used in the hardening of certain fats in the manufacture of
lard substitutes, is said to destroy it completely.

~"Water Soluble B."~--The second vitamine discovered in milk and
believed to be identical with the Funk vitamine is more widely
distributed than the "A" vitamine. For this reason it is not so likely
to be deficient in the diet as is found to be the case with the "A." A
glance at the table shows that the best sources outside of yeast are
the seeds of plants and the milk and eggs of animals. In beans and
peas the "B" vitamine is distributed throughout the entire seed, but
in the cereal grains it is found chiefly in the embryo. As a result,
bread made fr