the Action of Poisons on the Aiwnul System. 287 



frequently found tntangled in the mucus, or in the extra- 

 vasalcd blood; but where this was not the case, I have 

 never known, in an animal that was capable of vomiting, 

 that arsenic could be detected in the contents of the sto- 

 mach after death.' though examined by the most accurate 

 chemical tests. As some substances when taken internally 

 are separated from the blood very soon afterwards with the 

 urine,! lliought it probal)le that arsenic might be separated 

 with the urme also ; hut Mr. Brande (to whom I am 

 indebted for assistance on this, as well as on many other 

 occasions,) could never detect the smallest trace of arsenic 

 in it. 



IV. Experiments with the Muriate of Barytes. 

 When barytes is taken into the stomach, or api>lied to a 

 wound, it is capable of destroying life; but when in its 

 uncombined state its action is very slow. The muriate ot 

 barytes, which is much more soluble than the pure earth, 

 is (probably on this account) a much more active poison. 



Experiment 5. — Ten grains of nmriate of barytes rubbed 

 verv fine, and moistened with two drops of water, were 

 applied to two wounds in the thigh and side of a rabbit. 

 In four minutes he was evidently under the influence of 

 the poison. In a short time he became giddy: then his 

 hind legs were paralysed ; and he gradually fell into a state 

 of insensibility, with dilated pupils, and lay, in general 

 motionless, but with occasional convulsions. The pulse 

 beat 150 in a minute, but feeble, and it occasionally inter- 

 mitted. He was apparently dead in twenty minutes from 

 the application of the poison ; but on opening the chest 

 the heart was found still acting, and nearly three minutes 

 elapsed before its action had entirely ceased. 



Experiment 6. — An ounce and an half of saturated solu- 

 tion of muriate of barytes was injected into the stomach of 

 a full grown cat, by means of an elastic gum tube. In a 

 few mmutes it operated as an emetic. The animal became 

 giddy, afterwards insensible, and lay with dilated pupils, in 

 general motionless, but with occasional convulsions. At 

 the end of sixty-five minutes, from the beginning of the 

 experiment, he was apparently dead; but the heart was still 

 felt through the ril s acting one hundred times in a minute. 

 A tube was introduced into the trachea, and the lungs were 

 inflated about thirty-six times in a minute ; but tlic pulse 

 Hunk notwithstanding, and at the end of seven minutes the 

 circulation had entirely ceased. 



From these experiments I was led to conclude that the 

 principal action of the muriate of barytes is on the brain; 



but 



