AND ANIMAL LIFE. 245 



neons fluid occasions these consequences in the 

 delicate and nervous structure of the brain, it still 

 remains for some time a stimulus to the heart, 

 because this is differently organized. But it not 

 unusually happens that the dose is sufficiently 

 great to enfeeble the motions of this organ, at 

 the same time that it disorders the functions of 

 the brain. 



CCLXVI. I have observed in many experi- 

 ments performed on rabbits, that a small quanti- 

 ty of opium, in the greater number of instances, 

 augments the action of the heart for a short pe- 

 riod, while a greater proportion almost imme- 

 diately diminishes the force and frequency of its 

 contractions. If such circumstances occur in an 

 animal made insensible, it is reasonable to sup- 

 pose that the same agent operates in a similar 

 manner upon the animal economy possessed of 

 its ordinary powers. 



CCLXVII. When an individual or animal is 

 in a state of stupor, the breathing is irregular or 

 imperfect. This would seem to arise from the 

 blunted sensibility of the cerebrum to impressions com- 

 municated in health by the nerves belonging to the 

 function of respiration. M y experiments have been 

 made on rabbits ; and I have observed, when these 

 were stupified, that they appear for a while to 

 forget to breathe y until the accumulation of blood in 

 the lungs becomes painful 9 or the necessity of air im~ 

 perative. The sensation arising from one of these 



