394 Prof. Chrjstison on the Poisonous Properties of Hemlock, 



length of time. I have seen spontaneous contraction of the ven- 

 tricles of the heart go on ten minutes, twenty minutes, nay, even 

 thirty minutes, after death in the rabbit ; and have witness- 

 ed unequivocal contraction of the auricles when scratched even 

 so late as after an interval of sixty minutes. The most striking 

 illustration, however, of the integrity of the function of the heart 

 is obtained by keeping up respiration artificially when it has 

 ceased : After the breathing had almost ceased in seventeen mi- 

 nutes in a dog poisoned with six drops through a wound, and 

 when two minutes more would undoubtedly have put an end to 

 life, artificial inflation of the lungs was commenced, and conti- 

 nued with occasional intervals for thirty-five minutes. During 

 all that time the heart beat with its natural force, except when 

 the inflation of the lungs was suspended ; — the animal remaining 

 all the while in a state of paralytic flaccidity, interrupted only by 

 slight muscular twitches. It appears probable that there is 

 scarcely any limit to the maintenance of the circulation under 

 artificial breathing, except what may arise from the difficulty of 

 imitating exactly the natural respiration, as well as from the se- 

 veral causes which occasion cooling of the body. There is little 

 doubt, therefore, that where the dose of the poison is not very 

 great, animation may be restored by maintaining the function of 

 respiration artificially till the deleterious agent or its effects be 

 thrown off, — just as in some other forms of narcotic poisoning. 

 And when we consider the whole physiological phenomena, it 

 will appear that this is the only treatment which promises mate- 

 rial success. 



There are several other physiological facts relative to the 

 action of this poison, which are not devoid of interest, but which 

 it would be tedious to dwell on here. They will be best exa- 

 mined by consulting the Appendix of experiments. This de- 

 partment of my subject, therefore, may now be concluded with a 

 few remarks on the question, through what channel the action of 

 conia on the spinal chord is accomplished : Does it act by being 



