392 Prof. Curistison on the Poisonous Properties of Hemlock, 
poisoning; but this is not an essential phenomenon. ‘The mus- 
cular contractility of parts directly acted on,—as when a volun- 
tary muscle, a loop of intestine, or the heart, is brushed over 
with conia or its muriate,—is sometimes impaired, sometimes al- 
most immediately annihilated. But this effect, as will be evi- 
dent from the details of the experiments, is not invariable. Un- 
der the remote or indirect action of the poison, the muscular 
contractility remains altogether unaffected: when an animal is 
killed with the poison applied to the eye, a wound, or the like, 
both the voluntary and involuntary muscles contract for a long 
time after death, when stimulated, either directly or through the 
medium of their nerves, by mechanical irritation or by galvanism. 
The blood undergoes no apparent alteration, except those inci- 
dental to death by asphyxia; it coagulates firmly after death, 
if immediately withdrawn from the bloodvessels. The heart, 
contrary to Grrcrr’s statement, remains wholly unaffected,— 
contracting vigorously for a long time after all motion and respi- 
ration and other signs of life are extinct,—and containing after 
death, not florid, but dark blood in its left cavities. The exter- 
nal senses continue little, if at all, impaired, till the breathing 
is nearly arrested ; and volition is also retained. The action of 
conia, in short, is exerted chiefly on the spinal chord. In its na- 
ture that action is the counterpart of the action of nux-vomica 
and its alkaloid strychnia. Strychnia irritates the spmal chord, 
producing violent, permanent spasm of the muscles, and death 
by asphyxia from spasmodic fixing of the chest. Conia, on the 
contrary, exhausts the nervous energy of the spinal chord, pro- 
ducing general muscular paralysis, and asphyxia from relaxation. 
Few poisons equal conia in subtilty or swiftness. A single 
drop put into the eye of a rabbit killed it in nine minutes ; three 
drops used in the same way killed a strong cat in a minute and 
a-half; five drops poured into the throat of a small dog began to 
act in thirty seconds, and in as many seconds more motion and 
respiration had entirely ceased. But the most extraordinary evi- 
