288 Experiments and Observations on 



bnt in the first the pulse was feeble and intermitting; irt 

 the second, although the artificial respiration was made 

 with the greatest care, the circulation could not be main- 

 tained more than a few minutes. These circumstances led 

 me to suspect, that although this poison operates principally 

 on the brain, it operates in some degree on the heart also. 

 Further experiments confirmed this suspicion. In some of 

 them the pulse soon became so feeble, that it could he 

 scarcely felt ; and its intermissions were more frequent ; 

 but in all cases the heart continued (o act after respiration 

 had ceased ; and the cessation of the functions of the brain 

 was therefore always the immediate cause of death. Whew 

 I employed artificial respiration, after death had apparently 

 taken place, I seldom was able to prolong the heart's action 

 beyond a few minutes. In one case only it was maintained 

 for three quarters of an hour. I never by these means 

 succeeded in restoring the animal to life, although the ex- 

 periments were made with the greatest care and in a warm 

 temperature. In some instances, after the artificial respi- 

 ration had been kept up for some time, there were signs of 

 the functions of the brain being in some degree restored} 

 but the pulse notwithstanding continued to diminish in 

 strength and frequency, and ultimately ceased. I shall 

 detail one of these experiments, as it serves to illustrate the 

 double action of this poison on the nervous and vascular 

 systems. 



Experiment 7. — Some muriate of barytes was applied to 

 a wound in the side of a rabbit. The usual symptoms 

 took place, and at the end of an hour the animal was ap- 

 parently dead ; but the heart still continued to contract. 

 Ee was placed in a temperature of 80°, and a tube being 

 introduced into the nostril, the lungs were artificially in- 

 flated about thirty-six times in a minute. 



When the artificial respiration had been maintained for 

 four minutes he appeared to be recovering ; he breathed 

 voluntarilv one hundred limes in a minute, and showed 

 sisns of sensibility. The artificial respiration was discon- 

 tinued. The voluntary respiration continued about nine 

 minutes, when it had ceased, and the animal was again ap- 

 parently dead ; but the pulse continued strong and frequent. 

 The lungs were again artificially inflated. At the end of 

 four miiiutes the animal once more breathtd voluntarily 

 one hundred times in a minute, and repeatedly moved his 

 limbs and eye-lids. The pulse became slower and more 

 feeble. 



In a few minutes the voluntary respiration again ceased, 



aud 



