416 Prof. Christison on the Poisonous Properties of Hemlock, 



ence of a firm extract. This extract had a beautiful green colour, and a faint, 

 sweetish, herbaceous odour, which gave place to a powerful odour of conia, when it 

 was rubbed with solution of caustic potassa. It weighed seventy grains. 



Thirty-one grains were dissolved in the same quantity of water, and the solution 

 was injected between the skin and muscles of the back of a rabbit, care having 

 been taken to detach them previously with the finger ; and the poison was secured 

 by a ligature. The animal immediately cried. In a minute and a half there was 

 trembling and stiffness of the hind legs, hurried breathing, general languor, but 

 no insensibility. In two minutes it fell down, with the chest flaccid, and the 

 respiration diaphragmatic, and becoming quickly more and more limited in extent. 

 In four minutes there were some convulsions of the hind-legs, and tossing back of 

 the head, renewable by pulling the legs. The eyelids winked when the hand ap- 

 proached the eye, and the snout was twitched when the whiskers were pulled. In 

 five minutes respiration ceased. The usual twitches of asphyxia followed for two 

 minutes more. 



The body being then laid open, the heart was found in nine minutes contracting, 

 though not vigorously, and it was somewhat gorged. The blood flowed out as 

 dark from the left as from the right side, and coagulated as usual. 



Exp. XV. Thirty-one grains of the same extract, similarly dissolved, were in- 

 jected between the skin and muscles of a stout small dog, five months old. In three 

 minutes and a half the hind-legs were weak, and rather stiff, and in six minutes the 

 fore-legs also. In seven minutes the bowels, and in nine minutes the stomach, were 

 evacuated. In eleven minutes the breathing was diaphragmatic, and the chest 

 flaccid ; the animal had great difficulty in rising, from extreme muscular debility ; 

 and it made efforts to vomit, confined, however, to the diaphragm, — the muscles of 

 the chest and parietes of the abdomen remaining flaccid. In fifteen minutes the 

 breathing was slower and more limited. The legs were slightly twitched at times, 

 but in the intervals paralytic. The efforts to vomit had ceased. The eyelids were 

 quite active when the eye was approached with the hand. Occasional efforts were 

 made to change posture as if from uneasiness, but ineffectually ; and the same re- 

 sult followed in whatever position it was placed. In twenty minutes the respiration 

 ceased ; and then the eyelids for the first time became insensible. Convulsive 

 twitches followed for two minutes more. 



The chest was then laid open. In twenty-three minutes the heart was contracting 

 feebly, and was gorged. Stronger contractions took place when the pericardium 

 was slit open. Dark venous-like blood issued from the left ventricle when it was 

 opened, and soon coagulated firmly. In thirty minutes the muscles of the chest 

 and the diaphragm contracted strongly, when either the muscles themselves, or their 

 nerves, were pinched. 



Exp. XVI. Thirty-three grains of a different alcoholic extract, also of great 

 strength, as proved by trituration with solution of caustic potassa, were dissolved in 



