414 Prof. Christison on the Poisonous Properties of Hemlock 



II. Experiments with Muriate qfConia. 



Exp. X. Four drops of conia, neutralized with diluted muriatic acid, or rather with 

 the faintest excess of acid, were introduced through a small wound into the cellular 

 tissue behind the fore-shoulder of a strong rabbit. In fifteen seconds, all the legs 

 became for a few seconds somewhat stiff, then paralyzed, and the animal fell down 

 prostrate, flaccid, entirely palsied, but affected occasionally with rather brisk con- 

 vulsive twitches, renewable by touching the body. In one minute the respiration 

 was entirely diaphragmatic ; and in ninety seconds it ceased altogether. For two 

 minutes more the usual convulsive twitches of death by asphyxia presented them- 

 selves. The eyes were quite sensible till the breathing ceased ; after which the lids 

 did not contract even when the cornea was touched. 



In four minutes, the chest being laid open, the heart was seen contracting briskly 

 in all its parts ; and the vivacity of its contractions was not affected by spreading 

 solution of muriate of conia over the heart. In seven minutes the diaphragm, and 

 the adductor muscle of the thigh, did not contract when their respective nerves were 

 galvanized ; but both contracted freely when galvanism was transmitted from their 

 nerves to their substance. Even twenty minutes after the poison was applied, the 

 heart continued its contractions briskly, the left side acting as well as the right. 

 The vermicular movement of the intestines was also at that time active. 



Exp. XI. The preceding experiment was repeated with two drops of conia, ex- 

 actly neutralized with muriatic acid ; but the rabbit was smaller and younger. In 

 fifteen seconds the animal, which had been sitting, rose with the hind-legs stiff; but 

 paralysis of these legs instantly succeeded, the fore-legs became similarly affected, 

 complete prostration and general palsy ensued, and the breathing was short, slow, 

 laboured, and diaphragmatic. So far as could be judged the animal was sensible. 

 In sixty seconds the breathing ceased, without any previous convulsive movements. 

 Convulsive twitches followed as usual. 



In two minutes the chest was laid open. The heart contracted vigorously in all 

 its parts. Even in thirty minutes the force of its contractions was little diminished. 

 In forty-two minutes the auricles alone continued to contract a little. The blood 

 in the left side of the heart was as dark as in the right side, fluid, and coagulable. 



The tenth and eleventh experiments, when compared with the 

 fifth, show that conia is considerably more rapid in its action 

 when neutralized than when free. I do not know any variety of 

 death, in which the heart remains so long and so remarkably con- 

 tractile as these experiments show to be the case in poisoning 

 with muriate of conia 



