236 LECTURE VL 



I have been induced thus briefly to ad- 

 vert to the functions of the kidney, because 

 the quantity and quality of its products 

 can be ascertained, and thus throw light 

 upon the subject of secretion in general. 

 When water abounds in the blood, whether 

 from more being imbibed from the diges- 

 tive organs, or less being carried off from 

 the surfaces of our bodies, the quantity 

 separated by the kidney is proportionately 

 increased, and vice versa. Thus do the se- ' 

 cretions become vicarious to one another, 

 and conjointly tend to maintain the proper 

 quantity and quality of the circulating fluids. 



The qualities of the urine also demon- 

 strate how much secretion is affected by 

 different states of the nervous system in 

 general. When the kidney is rendered 

 irritable from various causes, and persons 

 are in that state usually termed hysteri- 

 cal, it scarcely separates any thing but 

 water from the blood, which is, indeed, 

 produced in an inordinate quantity ; and it 

 is probable, that a different state of the 

 nervous system, may render the kidney 



