AND ANIMAL LIFE. 417 



quickly brings on the train of symptoms which 

 the lancet had previously removed, and not the 

 diminution of the excretions, the usual quantity 

 of the ingesta remaining the same, as imagined 

 by Dr CULLEN. 



DVI. The influence of heat and cold upon the 

 body shows the extensive sympathy which is ex- 

 perienced by every part of the system in conse- 

 quence of the changes of circulation. When heat 

 is applied to the surface of the body, it stimu- 

 lates the capillary vessels to increased action ; 

 and this condition is communicated to the larger 

 vessels, and afterwards to the lungs themselves. 

 When the heart and the respiratory function 

 are indirectly excited, as in this instance, they 

 react upon the sanguineous jiuid^ and transmit it in 

 greater abundance to the capillary vessels. Dur- 

 ing this reciprocal action, the remote and exter^. 

 nal parts of the body receive a greater quantity 

 of blood ; but the rapidity of the motion with 

 which it circulates in the lungs over excites or 

 disorders the minute vessels, which chiefly com- 

 pose their substance, and gives rise to hemor- 

 rhagy. Stimuli taken within, and exercise of 

 every description, produce the same effect. If 

 we consider that the organization of the lungs 

 is extremely delicate, and that the capacity and 

 operation of these must be in harmony with the 

 different branches of the arterial and venous cir 



Dd 



