and prevent scurvy. This evidence was not considered convincing, however,
since in his experiments milk was given freely. Furthermore, Cohen and
Mendel demonstrated that in their experiments pure lactose neither
prevented nor cured scurvy while Harden and Zilva could find no
antiscorbutic value in either cane sugar, fructose, or sirup. These
authors believed and stated that Pitz's results were entirely attributable
to the free use of raw milk.

As this milk factor came increasingly to the attention in the controversy
it was natural that students began to reexamine this product more
carefully. The vitamine advocates at first believed that its potency as an
antiscorbutic was of course due to the vitamines already found present
therein, viz., the "A" or the "B." But there began to be difficulties with
this view. Hess found that eggs and cod-liver oil, both rich in "A" were
of no value as scurvy cures. These experiments eliminated the "A" as the
curative factor. Cohen and Mendel used a mixture of yeast and butter in
their experiments without success. These experiments threw doubt on the
"B" as a curative factor. Studies in heated milk had also shown that the
scurvy curing power was destroyed by such procedures as heating and that
pasteurized milk was not as good as raw milk. This heating on the other
hand did not destroy the antineuritic power of the milk nor its growth-
stimulating properties. The combined result of all these studies was to
eliminate both the "A" and the "B" as the vitamines with antiscorbutic
power without suggesting a better hypothesis than McCollum's.

Gradually, however, it became evident that while scurvy is not prevented
by either of these vitamines Funk's hypothesis and Holst and Frohlich's
experimental evidence was correct and McCollum's view wrong. The answer
lay in the discovery of a third vitamine, water-soluble like "B" but
otherwise of entirely different behavior and properties. J. C. Drummond of