290 OF THE SECRETIONS IN GENERAL. , 



ance in the business of secretion. In every secreting 

 organ, it absorbs, for the purpose of transmission to the 

 blood, a fluid which is, as it were, contaminated by 

 the secretion of the part: v. c. a bilious fluid in the 

 liver; a spermatic in the testes. A constant circle 

 would, therefore, appear to exist in the secretory sys- 

 tem, so that the elements of the secretions are inces- 

 santly carried to the blood from the secreting organs, 

 and, when they return to the organs, are the more 

 easily attracted by a species of affinity, and draw with 

 them those parts of the blood whose nature is related 

 to their own. 



478. The blood from which some secretions are pro- 

 duced, is endowed with peculiar qualities. The bile, 

 for example, is derived from blood which contains an 

 abundance of carbonaceous element. 



479. We omit other assistances afforded to certain 

 secretions; v. c. congestion and derivation, so striking 

 in the secretion of milk, &c. 



480. There is this difference among the various 

 fluids secreted by the organs and powers now de- 

 scribed, that some pass to the place of their desti- 

 nation immediately, while others are deposited in re- 

 ceptacles, and detained there for a length of time, 

 becoming more perfect before their excretion. The 

 milk in its ducts, the urine, bile, and semen in their 

 respective bladders, and in some degree the serum of 

 the vesicles of De Graaf, are examples of this. 



