412 Pellagra-Producing Diets. V 
of time, may produce an injurious effect on certain organs of the body. 
This hypothesis does not rule out the possibility that a dietary deficiency 
. . . [vitamines] . . . . may play a réle in the production and 
treatment of pellagra.”’ 
“One will have to consider very seriously: (1) A deficiency or absence 
of certain vitamines in the diet. (2) The toxic effect of some substances, 
as aluminum, which occur in certain vegetable foods. (3) A deficiency 
of the diet in certain amino-acids.”’ 
Chittenden and Underhill (2) produced in dogs a condition which they 
describe as closely similar to pellagra in man, by feeding a diet consisting 
of cooked (dried) peas, cracker meal, and cottonseed oil. Their views 
concerning the number of diseases which fall into the same category with 
beri-beri, that is in being caused by the lack of specific protective sub- 
stances, are formulated as follows: 
‘“The absence or deficiency of these substances (‘vitamines’) may lead 
to a variety of metabolic disturbances which have been designated by 
different names as beri-beri, scurvy, pellagra, etc., and which may be 
grouped together as ‘deficiency diseases.’’’ They concluded from their 
numerous experimental data that, ‘‘From the facts enumerated the con- 
clusion seems tenable that the abnormal state may be referred to a de- 
ficiency of some essential dietary constituent or constituents, presumably 
belonging to the group of hitherto unrecognized but essential components 
of an adequate diet.’’ 
As a result of studies with diets composed of purified food- 
stuffs supplemented with fats of the growth-promoting and non- 
growth-promoting classes, and with alcoholic and water extracts 
of plant tissues (4) and also with the addition of small amounts 
of various natural foods (5), we were led to the conclusion that 
there are possible of classification two still unidentified food 
complexes which are essential in the diet, and we introduced the 
terms fat-soluble A and water-soluble B to designate them (6). 
The prefixes ‘‘fat-soluble”’ and ‘‘water-soluble’ have now be- 
come generally adopted by other investigators, although there is 
still lack of uniformity in the terminology in other respects. 
There are not less than twenty different terms in the literature of 
the last 2 or 3 years to designate these two substances, or as a few 
authors seem to believe, groups of substances of unknown nature.! 
1 Recently Emmett and McKim (7) have argued in favor of the exist- 
ence of a special ‘‘vitamine’’ for maintenance and another or others for 
growth. We are not able to see in the experimental data which Emmett 
and McKim present any evidence in support of the interpretation which 
the authors put upon their data. | 
