58 Water-Soluble B 
controlled experiments all indicates that the dietary essential 
termed by us the water-soluble B is not readily destroyed by 
aging, exposure to the atmosphere, or by heat at 100—112°C. (5) 
in neutral reaction. The experience of all investigators who have 
employed precipitation methods for the concentration of this 
substance indicates that it is very stable in dilute acid solu- 
tions. Indeed the statement has been made by Vedder and 
Williams (18) and by Funk that hydrolyzed preparations were 
more active than before hydrolysis. 
It is possible to suggest an alternative explanation for Wil- 
liams’ hypothesis which will account for the occasional relief of 
polyneuritic pigeons by such a list of unrelated substances as 
nicotinic acid, certain pyrimidines, certain purines, and certain 
hydroxypyridines. The following explanation, while purely specu- 
lative, may possibly account for the recorded observations and 
assist in clarifying the confusing data relating to this subject. 
Histological methods have shown that in polyneuritic animals 
there is a degeneration of the motor cells of the cord. This change 
is progressive; some cells present the normal appearance while . 
others in the same field are degenerated. It would appear plau- 
sible that when the motor cell changes have reached a certain 
point loss of function supervenes and paralysis results. There 
still remain in the cord of a paralyzed animal motor cells which 
appear normal when stained and which may be capable of re- 
storing the motor functions of the muscles when influenced by 
substances which stimulate them to heightened sensitiveness. 
In other words, the temporary relief of polyneuritis may be the 
result of the pharmacological action of certain substances rather 
than a response with renewed function of cells which have been 
subjected to a selective fast and later have been supplied with the 
“missing food complex. If this line of reasoning could be shown 
to be valid, it would follow that experiments with pure chemical 
substances of known constitution, with a view to finding by good 
fortune the one playing an important physiological réle, might 
be entirely misleading unless 7t were shown that the ‘‘cure’ was 
permanent. For such complete proof it is necessary to demon- 
strate the resumption of growth and maintenance of health as 
long as the substance is supplied in the food mixture. Animals 
which have been brought into a critical condition where death is 
