X.—ABSORPTION OF ARSENIC BY THE Brain. By R. H. Cuirren- 
DEN AND Hersert E. Smita, M.D. 
Some time since one of us* advanced the view that the amount of 
arsenic present in the brain, in cases of arsenical poisoning, is an in- 
dex to the form in which the poison was taken, viz: whether in a 
readily soluble and diffusible form, such as sodium arsenite, or in a 
comparatively insoluble form, as arsenious oxide or aceto-arsenite of 
copper. The original experiments of Scolosuboff+ on animals, with 
sodium arsenite, plainly showed the capability of nerve tissue for the 
absorption of arsenic ; yet the recorded observations of toxicologists 
tend to show, as a rule, the presence of but traces of this metal in 
cases of arsenic poisoning, either acute or chronic. Scolosuboff’s re- 
sults are, however, undoubtedly correct ; arsenic when taken in a very 
soluble and diffusible form without doubt does accumulate in the 
brain, but in our opinion only when in that condition, and thus in 
the more common forms of poisoning with the white oxide or other 
insoluble forms of arsenic, but a trace of the poison is to be found in 
the brain at any one time. 
With a firm belief in the truth of the above statement, founded on 
personal experience and the recorded results of other workers in this 
field, it was maintained by one of us in a previous paper{ that the 
presence of weighable amounts of absorbed arsenic in the brain may 
be taken as an indication of the administration of a soluble form of 
the poison. Experiments on animals tend to show the correctness of 
the theory and the results of toxical investigations, so far as our 
knowledge extends, contain nothing contrary to this view. If true, 
we ought never to find under any circumstances an accumulation of 
arsenic in the brain, after the administration of an insoluble form of 
the poison. Hence, the study of arsenic cases, where the form of 
poison is known, is of great importance in this connection. 
We have had a recent opportunity of adding two more cases to 
* Chittenden, Amer. Chem. Jour., vol. v, p. 8; and Medico-Legal Journal, vol. ii, 
p. 237. 
+ Bulletin de la Société Chimique de Paris, vol, xxiv, p. 125, 
¢ Chittenden, loc. cit. 
