EK. V. McCollum and N. Simmonds HT 
preparations. Careful reading of the literature relating to 
studies on polyneuritis in birds revealed so many confusing state- 
ments that we decided to attempt to perfect the technique for 
employing the rat for such studies. We feel convinced that a 
satisfactory procedure has been developed. 
Funk (7) says that when the curative fraction obtained from 
either dry yeast or rice polishings was administered orally or 
subcutaneously to beri-beri pigeons, “the animals recovered very 
speedily, often in 2-3 hrs., but it was found impossible to keep 
them permanently on polished rice even when injections were 
repeated every few days.” 
Williams (8) has pointed out, and our experience. harmonizes 
with his, that pigeons restricted to a diet of polished rice do not 
all run the same course. Many never develop acute polyneuritis, 
but waste away and die of starvation. Such birds are of no value 
in experimental work. Some, he states, recover temporarily 
from an acute attack without any treatment. 
Eijkman (9) injected doses of 20 to 40 mg. of a mixture of one 
part NaCl and three parts KCl into chickens and pigeons and 
observed cures in pigeons but not in chickens. These results 
seem to justify the belief that temporary relief from paresis is less 
satisfactory as a test for the physiologically indispensable sub- 
stance water-soluble B than is our method in which the diet is 
_ properly planned so as to be satisfactory for growth except for the 
absence of the one unidentified substance. With our diet re- 
sumption of growth actually takes eet on the addition of the 
water-soluble B to the diet. 
Antineuritic properties have been attributed to nicotinic acid 
(10) and to adenine (11), betaine, allantoin, and certain pyrimi- 
dines (12), and Williams has observed curative action in a certain 
isomer of a-hydroxypyridine (8). He has attempted to account 
for all of these observations by assuming that the needs of the 
animal are for a specific type of labile isomerism rather than a 
specific chemical complex as in the case of certain amino-acids in 
their relation to protein metabolism. That this explanation 
should be the correct one we believe improbable. The anti- 
neuritic substance employed by Williams was relatively labile, 
and passed easily into a form which possessed no curative prop- 
erties. In the natural foods the evidence available from well 
