INTUMESOENTIvE. 581 



CHAP III. OF WATERY SWELLINGS, OR 

 DROPSIES. 



MDCXLV. A preternatural collection of serous or watery 

 fluids is often formed in different parts of the human body ; and 

 although the disease thence arising be distinguished according to 

 the different parts which it occupies, yet the whole of such col- 

 lections come under the general appellation of Dropsies. At 

 the same time, although the particular instances of such collec- 

 tion are to be distinguished from each other according to the 

 parts they occupy, as well as by other circumstances attending 

 them, yet all of them seem to depend upon some general 

 causes, very much in common to the whole. Before proceeding, 

 therefore, to consider the several species, it may be proper to 

 endeavour to assign the general causes of dropsy. 



MDCXLVI. In persons in health, a serous or watery fluid 

 seems to be constantly poured out, or exhaled in vapour, into 

 every cavity and interstice of the human body capable of receiv- 

 ing it ; and the same fluid, without remaining long or being ac- 

 cumulated in these spaces, seems constantly to be soon again 

 absorbed from thence by vessels adapted to the purpose. From 

 this view of the animal economy, it will be obvious, that if the 

 quantity poured out into any space happens to be greater than 

 the absorbents can at the same time take up, an unusual ac- 

 . cumulation of serous fluid will be made in such parts; or though 

 the quantity poured out be not more than usual, yet if the ab- 

 sorption be anywise interrupted or diminished, from this cause 

 also an unusual collection of fluids may be occasioned. Thus, 

 in general, dropsy may be imputed to an increased effusion, or 

 to a diminished absorption ; and I therefore proceed to inquire 

 into the several causes of these. 



MDCXLVII. An increased effusion may happen, either 

 from a preternatural increase of the ordinary exhalation, or from 

 the rupture of vessels carrying, or of sacs containing, serous or 

 watery fluids. 



MDCXLVIII. The ordinary exhalation may be increased 

 by various causes, and particularly by an interruption given to 

 the free return of the venous blood from the extreme vessels of 



