33 
might be brought about. If we suppose that alcohol is normally 
oxidized by reactive chemical groups analogous to side chains, then 
the tolerance may be thought of as due to an increase in the number 
of these groups and it is very natural to suppose that an organism 
that has acquired increased power of oxidizing the ethyl group of 
alcohol has also acquired increased power of oxidizing the methyl 
group of acetonitrile. This is but a suggestion; yet it should be 
remembered that Ehrlich proposed his side-chain theory of the 
structure of living matter in connection with his work on oxidation 
and sometime before he began his work on immunitv.® 
This explanation is very similar to the one recently suggested by 
Vaughan^ for the Rosenau- Anderson ” ^ or “Theobold Smith” 
phenomenon (the hypersusceptibility of guinea pigs to horse serum 
after a previous injection of horse serum). Vaughan supposes the 
proteid molecules (of horse serum, for example) to contain toxic 
groups; the first time the horse serum is injected the body breaks up 
the molecule but slowly, so that the toxic groups are set free slowly, 
and there are no symptoms of intoxication. But if a second injection 
is made after ten days ‘‘the cells tear the molecule to pieces quicker 
than before; this sets the poisons free quicker and the animal dies.” 
These experiments with alcohol and acetonitrile are of interest 
in another connection. The greatest advance in recent years in 
our knowledge of the physiological action of alcohol has been the 
clear demonstration that alcohol is oxidized in the body and may 
replace fats and carbohydrates and, to a certain extent, the proteids 
of an ordinary diet. So clear has been this demonstration that the 
view that alcohol, in moderate amounts, should be regarded as a food 
is almost universally accepted by physiologists, and the drift of 
opinion is certainly toward the view that it is in all respects strictly 
analogous to sugar and fats, provided always that the amount used 
does not exceed that easily oxidized by the body. Under these 
premises it would be expected that alcohol in a diet would have the 
same effect upon an animars susceptibility to acetonitrile as has dex- 
trose, for example. This is by no means the case, however; on the 
contrary, the action of these substances in this regard is entirely 
different. Mice fed upon oats soaked in a solution of dextrose or 
upon cakes containing considerable dextrose, or upon rice, show a 
very distinct increase in their resistance to acetonitrile; such mice 
a Ehrlich, Das Sauerstoff-Bediirfniss des Organismus, 1885. 
^ Journ. Amer. Med. Assoc., v. 47, p. 1009; 1906. 
c Bulletin No. 29, Hygienic Laboratory, 1906. 
Otto, V. Leuthold-Festschrift, 1906. 
