orange juice.

There are other diets that have been given for this purpose, e.g., Holst
and Frohlich induced scurvy by restricting animals to an exclusive diet of
cereals (oats or rye or barley or corn). Hess and Unger have used hay,
oats and water given ad libitum. All of these and others are subject to
criticism on the basis that they are not necessarily adequate in other
food factors and may therefore not be fair bases for testing the
antiscorbutic powers of the unknown combined with them. Abels has recently
shown that scurvy increases susceptibility to infections and believes that
the scurvy hemorrhages are brought about by the toxic effects of
infection. It is therefore desirable in testing for antiscorbutic power
that the basal diet be itself as complete as possible in all factors
except the absence of "C."

The study of rickets has already progressed to the stage of calculating
rickets-producing diets and the methodology is identical with that for
scurvy but this phase of testing still lacks evidence of an antirachitic
vitamine and in that uncertainty it is hardly worth while to elaborate
these diets here. The British diets are all based on Mellanby's contention
that the "A" vitamine is the antirachitic vitamine. This view is not yet
accepted by American workers.

In concluding this chapter it is sufficient to state that with our present
methodology the accumulation of data for evaluating the vitamine content
of various foods is still far from satisfactory and from the chemist's
viewpoint the methodology is most unsatisfactory as a means of testing
fractional analyses obtained in the search for the nature of the
substance, both because of the time consumed in a single test and from the
difficulty of using the fractions in feeding experiments when these