AND ANIMAL LIFE. 415 



DIL The question has frequently been agitat- 

 ed, How hemorrhagy contributes to a plethoric 

 state of the system ? The fact can scarcely be 

 doubted ; and the knowledge of it has diminish- 

 ed materially the long-established custom of an- 

 nual depletion. It is observed by Dr CULLEN, 

 ft that the quantity of serous fluids being given, 

 the state of the excretions depends upon a cer- 

 tain balance between the force of the larger arte- 

 ries propelling the blood, and the resistance of 

 the excretories ; but the force of the arteries de- 

 pends upon their fulness and distention, chiefly 

 given to them by the quantity of red globules 

 and gluten, which are, for the greatest part, con- 

 fined to the red arteries ; and, therefore, the spo- 

 liation made by a hemorrhagy being chiefly of 

 red globules and gluten, the effusion of blood 

 must leave the red arteries more empty and weak. 

 In consequence of the weaker action of the red 

 arteries, the excretions are in proportion dimi- 

 nished, and therefore, the ingesta continuing the 

 same, more fluids will be accumulated in the lar- 

 ger vessels." 



Dili. If the above explanation be correct, one 

 would imagine that the ordinary means which 

 contribute to create a state of plethora would be 

 similar to those that produce a sudden return of 

 that condition. Eut we find that individuals 

 whose pursuits require great exercise, and whose 

 mode of life is extremely simple, are not unusual- 



