the Action of Poisons on the Animal Sijsterd. 289 



and the artificial respiration was resumed^. The pulse had 

 fallen to one hundred, and was feeble The animal again 

 breathed voluntarily; but he ceased to do so at the end of 

 five minutes. The lungs were inflated as before ; but he 

 did not give any sign of life, nor was tht pulse felt after- 

 waids. On opening the thorax, the heart was found to 

 have entirely ceased acting. 



A probe having been introduced into the spinal marrow^ 

 it was found thai by means of the Voltaic battery powerful 

 contractions might be excited, not only of the voluntary 

 muscles, but also of the heart and intestines; from which 

 it may be inferred, that the muriate of barytes, like arsenic, 

 afl^ects the circulation by rendering the heart insensible to 

 the stimulus of the blood, and not by destroying altogether 

 the power of muscular contraciion. 



The muriate of barytes affects the stomach, but in a less 

 degree than arsenic. It operates as an emetic in animals 

 that are capable of vomiting; but sooner when taken inter- 

 nally, than when applied to a wound. In general, but not 

 eojistantly, there are marks of inflammation of the inner 

 membrane of the stomach, but not of the intestine. la 

 many instances there is a thin layer of dark-coloured coa* 

 gulurn of blood lining the whole inner surface of the sto- 

 mach and adhering very closely to it, so as to have a good 

 deal of the appearance of a slough ; and this is independent 

 of vomitintr, as where I met with it, it occurred in rabbits. 



The same circumstances, from which it may be inferred 

 that arsenic does not produce its deleterious effects until it 

 has passed into the same circulation, leads to the same con* 

 elusion with regard to the muriate of barytes. 



V. On (he Effects of the Emetic Tartar. 



The effects of the emetic tartar so much resemble those 

 of arsenic and of muriate of barytes in essential circum- 

 stances, that it would be needless to enter into a detail of 

 the individual experiments mnde with this poison. 



When ap])lied to a wound in animals which are capable 

 of vomiting, it usually, but not constantly, operates very 

 speedily as an emetic ; otherwise I have found no material 

 difference in the symptoms produced in the different species 

 of animals which I have been in the habit of employing as 

 the subjects ot experiment. The symptoms are paralvsis, 

 drowHiness, and at last complete insensibilitv ; the pulse 

 becoints feeble; the heart continues to act after apparent 

 death ; its action may be maintained by means of artilicial 

 Aspiration ; but never for a loniier period than a few mi- 



• Vol.40. No. 174. Oc/. 1819.^ T nutes 



