264 IRRITABILITY 



arsenic acid, ammonia and substitution compounds of ammonia. 

 These substances do not follow the Meyer-Overton law of the 

 coefficient of distribution. \\t cannot consider them, therefore, 

 as narcotics. Future investigation will establish the existence of 

 a large number of substances belonging to this great group of 

 oxydation suppressing poisons, which are not narcotics. And 

 it is likewise certain that depressing substances will be found, the 

 depressing effects of which will not have their point of attack in 

 the oxygen exchange, but w'ill be shown to exist in other con- 

 stituents of the metabolic chain. Our research in these fields, as 

 already said, is still in the first beginnings and its perspective 

 reaches into infinite space. 



