THE RELATION OF DIET TO DISEASE 441 
coworkers showed that the oat kernel was low in inor- 
ganic salts and vitamine A and poor in the quality of its 
protein; but with these faults corrected it proved to be 
a complete food for rats. McCollum also found that 
scurvy developed more readily in animals if the physical 
properties of the diet favored constipation. He was able 
to delay the onset of the disease in guinea-pigs for a 
considerable period by the addition of mineral oil which 
has no food value, or phenolphthalein, a cathartic. At 
the same time, Jackson and Moore, (29) found the cecum 
of all guinea-pigs dying of scurvy, packed with putrefying 
feces. They were able to produce a mild type of the dis- 
ease by the injection of the diplococci isolated from the 
swollen joints. 
From these observations it seems safe to conclude that 
scurvy may not be purely a deficiency disease, or even a 
simple dietary one, although the presence of a vitamine 
influence is not excluded ; but it is probably the result of 
a bacterial invasion of tissues debilitated by a. faulty diet 
and by the toxins produced by the putrefactive bacteria 
developing in a diet unsuited to the anatomical demands 
of the alimentary tract. Tliis theory receives support 
from the fact that pasteurization destroys all aciduric 
bacteria, allowing only the spore-forming putrefactors 
to develop ; and from the fact that scurvy develops more 
frequently in children on stale pasteurized than on stale 
raw or boiled milk. In this Garden no suggestion of scurvy 
has been noted. 
Pellagra is very definitely a disease of poverty en- 
demic for years among the poor, especially in the moun- 
tains of Northern Italy. It has been under observation 
in the United States since 1907. So far as is known no 
cases have been observed among animals. Opinions dif- 
fer as to the role of diet in the etiology but the results 
of recent studies seem to show that uncomplicated cases 
of average severity clear up entirely on a diet rich in 
(29) Jour. Infect. Dis., 1916, XIX, 478. ~~~ 
29 
