232 VEGETABLE POISONS. 



wards the injection was repeated in the same quantity. The dog 

 then was sick, and threw up some of the infusion, with other mat- 

 ter, from the stomach ; he became faint, and died ten minutes 

 after the second injection. Immediately after respiration had 

 ceased, I opened the thorax, and found the heart extremely ex- 

 tended, and without any evident contraction, except of the appen- 

 dix of the right auricle, which every now and then contracted in a 

 slight degree. I divided the pericardium on the right side. In 

 consequence of the extreme distension of the heart, this could not 

 be done without irritating the fibres with the point of the scalpel. 

 Immediately both auricles and ventricles b<?gan to contract with 

 considerable force, so as to restore the circulation. Artificial re- 

 spiration was produced, and the circulation was kept up for more 

 than half an hour, beyond which time the experiment was not con- 

 tinued. 



We may conclude from these experiments, that the effect of the 

 infusion of tobacco, when injected into the intestine of a living 

 animal, is to destroy the action of the heart, stopping the circula- 

 tion and producing syncope. It appeared to me that the action of 

 the heart ceased even before the animal had ceased to respire ; and 

 this was confirmed by another experiment, in which, in a dog killed 

 by the infusiou of tobacco, I found the cavities of the left side of 

 the heart to contain scarlet blood, while in those of the right side 

 the blood was dark-coloured. This poison therefore differs mate- 

 rially from alcohol, the essential oil of almonds, and the juice of 

 aconite, which have no direct influence on the action of the heart. 

 The infusion of tobacco renders the heart iusensible to the stimulus 

 of the blood, but it does not altogether destroy the power of mus- 

 cular contraction, since the heart resumed its action in one instance 

 on the division of the pericardium, and I have found that the vo- 

 luntary muscles of an animal killed by this poison are as readily 

 stimulated to contract by the influence of the Voltaic battery, as if 

 it had been killed in any other manner. At the same time, how- 

 ever, that the infusion of tobacco destroys the action of the heart, 

 it appears to destroy also the functions of the brain, since these did 

 not return in the last experiment ; although the circulation was re- 

 stored, and kept up by artificial respiration. 



Since there is no direct communication between the intestinal 

 canal and the heart, I was at first induced to suppose that the lat. 



