
220 NATURE AND LIFE. 
ing the pupil of the eye when dropped into that organ, or 
introduced through the usual passages. An extremely mi- 
nute quantity of this active principle is enough to produce 
this phenomenon almost instantly, the importance of which 
Harley was the first to indicate. The exact knowledge 
of the effects of atropine, which, moreover, acts upon the 
whole nervous system, furnishes an explanation of the 
strange circumstances, among others the remarkable mad- 
ness, of which ancient authors speak when describing some 
cases of poisoning by belladonna. 
There exists a substance which exerts over the appara- 
tus of sight an influence directly opposed to that of atro- 
pine; this is the Calabar bean, the properties of which were 
discovered in 1863 by a skillful physician of. Edinburgh, 
Mr. Fraser. This seed, or rather the alkaloid contained in 
it, and which was isolated in 1865 by a French chemist, 
Vée, occasions so ‘powerful a contraction and narrowing 
of the pupil of the eye, that the orifice almost completely 
vanishes. This constriction of the pupil reaches its highest 
point about an hour after the active principle has been ad- 
ministered, and persists for about three hours, and then 
slowly disappears. This action upon the muscles govern- 
ing the movements of the pupil depends on the excitement 
of a particular nerve. Atropine paralyzes this nerve, thus 
occasioning dilatation of the pupil. There is thus an op- 
position between the active principle of the Calabar bean 
and that of atropine, and experience shows that the effects 
same time, the man who had brought him the poison touched him, and 
after a little while examined his feet and legs ; then, pressing one of his 
feet strongly, he asked him if he felt it ; Socrates answered, ‘No.’ After- 
ward he again pressed the lower part of his legs, and, thus advancing up- 
ward, he showed us that the body was growing cold, and becoming rigid. 
He still continued feeling, and said, ‘ Whenever it reaches the heart he 
will die.’ Already almost all the parts near the lower abdomen were 
chilled. Socrates then uttered a few words, then went into a convulsion, 
and died.”—P.arTo. 

