VEGETABLE POISONS. 233 



ter becomes affected in consequence of the infusion being conveyed 

 into the blood bv absorption. Some circumstances in the fo!. 

 lowing experiment have since led me to doubt whether this is the 

 case. 



Exp. 12. In a dog, whose head was removed, I kept up the 

 circulation by means of artificial respiration, in the manner already 

 described in the account of some experiments which T lately 

 communicated. I then injected into the stomach and intes. 

 tines nine ounces of infusion of tobacco. At the time of the 

 i:\jection, the body of the animal lay perfectly quiet and motion- 

 less on the table ; the heart acted regularly one hundred times in 

 a minute. Ten minutes afterwards tne pule rose to one hundred 

 and forty in a minute ; the peristaltic motion of the intestines was 

 much increased, and the voluntary muscles in every part of the 

 body were thrown into repeated and violent spasmodic action. The 

 joints of the extremities were alternately bent and extended ; the 

 muscles of the spine, abdomen, and tail alternately relaxed and 

 contracted, so as to turn the whole animal from one side to the 

 other. I have observed, in other instances, spasmodic actions of 

 the muscles, where the circulation was kept up by artificial respira- 

 tion, after the removal of the head, but not at all to be compared, 

 either in strength or frequency, with those which took place on this 

 occasion. I made pressure on the abdominal aorta for more than 

 a minute, so as to obstruct the circulation of the blood in the 

 lower extremities ; but the muscular contractions were not lessened 

 in consequence. Half an hour after the injection of the infusion, 

 the artificial respiration was discontinued. The heart continued to 

 act, circulating dark-coloured blood ; the muscular contractions 

 continued, but gradually diminished, in strength and frequency. I 

 tied a ligature round the vessels at the base of the heart, so as to 

 stop the circulation; nevertheless the muscular contractions still 

 coutuiued, though less frequent and forcible than before, and some 

 minutes elapsed before they entirely ceased. 



In this experiment, the disposition to contraction in the muscles 

 was very much increased, instead of being diminished, as in those 

 just related. If the infusion of tobacco influences the heart from 

 being absorbed into the blood, and thus coming into actual contact 

 with its fibres, tnere is no evident reason why the removal of the 

 brain, and the employment of artificial respiration, should occasion 



