LYMPHATIC SYSTEM. 197 



thence be led to a more correct notion about the causes of 

 those dropsies, which causes have been supposed to be either 

 an increased secretion, or an impeded absorption, or a rupture 

 of the lymphatic vessel ; none of which probably, strictly speak- 

 ing, gave rise to such morbid collections of water. For if 

 merely an increased secretion or an impeded absorption was 

 the cause of an ascites or an anasarca, then the fluid let out 

 should resemble that contained in these cavities in living ani- 

 mals. The same reasoning holds good against these dropsies 

 being occasioned by the rupture of a lymphatic vessel ; that is, 

 the fluid evacuated is not similar to what we found contained 

 in those vessels in our experiments, where the lymph jellied on 

 exposition to the air. 



And as we observed in those experiments, that these fluids 

 approached nearer to the nature of those found in dropsies, in 

 proportion as the animal was weakened, or reduced, as particu- 

 larly in the dog fed eight days on bread and water, is it not 

 therefore more probable, that in these kinds of dropsies there 

 is something more than an increased secretion, or an impeded 

 absorption? that is, there is a perversion of the secretion, or 

 the vessels throw out a flui.d different from the natural one; 

 which may happen, either from the exhalant arteries being 

 themselves altered by disease, so as to change the properties 

 of the fluid which passes through them, or from the mass of 

 blood being vitiated or abounding so much with water as to 

 affect this secretion j thence these dropsies are not primary dis- 

 eases, but the consequences of others, and a diseased liver, 

 spleen, or lungs, which so often accompany these dropsies, are 

 not so properly to be considered as giving rise to them by 

 causing a rupture of a lymphatic vessel, or obstructing the 

 course of the lymph, as by affecting chylification and sanguifi- 

 cation ; for when the liver, for example, is diseased, and the bile 

 deficient in quality or in quantity, the food not being properly 

 assimilated, may make a bad blood, which may affect the 

 vessels, and may let go its water into these cavities. 



But although from these considerations it seems probable 

 that an obstruction or rupture of the lymphatics is not the 

 cause of these dropsies, where a mere water is found in those 

 cavities, yet they may occasionally be the causes of others. If 

 a lymphatic should burst in a person in health, a dropsy may 



