polyneuritic methods with pigeons, viz., preventive and curative tests
with guinea pigs. The "C" vitamine is especially sensitive to heat and
this fact enables us to secure a "C" vitamine-free diet. La Mer, Campbell
and Sherman describe their methods as follows:

First select guinea pigs of about 300 to 350 grams weight. Test these with
the basal diet until you secure pigs that will eat the diet. Those that
will not eat it at first are of no use for testing purposes, for a guinea
pig will starve to death rather than eat food he doesn't like. Having
secured pigs that will eat they should on a suitable basal diet die of
acute scurvy in about twenty-eight days. Their basal diet is as follows:

_per cent_
Skim milk powder heated for two hours at 110 C. in an air
bath to destroy the "C" vitamine that might be present. . 30
Butter fat . . . . . . . . . . . . . . . . . . . . . . . . 10
Ground whole oats . . . . . . . . . . . . . . . . . . . . . 59
NaCl . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

They claim that when fruit juice addenda are given in minimal protective
doses and calculated to unit weight bases, the results are comparable in
precision to those of antitoxin experiments.

Old food should be removed every two days and replaced by new, cups being
cleaned at the same time. Since this is a scurvy-producing diet its use is
obvious. We can let the pig develop scurvy on it and then test the
curative powers of the unknown by adding it to the diet or we can add it
to the diet from the first and determine the dose necessary to prevent
scurvy; or we can determine its effect in terms of a known antiscorbutic
such as orange juice by combining it with measured quantities of the