General Diseases. 329 



" If water be injected in sonae quantity into the blood- 

 vessels of a living animal, the animal soon perishes — dying 

 generally by coma, or by suffocation ; and when the carcass 

 is examined the lungs are found to be charged with serous 

 liquid ; or water is discovered in the areolar tissue of some 

 •other part, or in the shut serous membrane. If, however, 

 the animal be first bled and then a quantity of water 

 injected equal to the quantity of blood abstracted, the 

 injection is followed by no serious consequences. 



" Facts like these throw, as it seems to me, a strong light 

 on a confesfsedly obscure part of pathology. It appears 

 that under various circumstances the blood-vessels may 

 receive a considerable and unwonted accession of watery 

 fluid, and that they are very prone to get rid of the redund- 

 ance. When they empty themselves through some free 

 surface, .their preternatural distention is relieved by a flux. 

 If, on the other hand, the surface be that of a shut sac, in 

 discharging their superfluity they cause a dropsy. Why 

 sometimes this organ and sometimes that is selected as the 

 channel by which the superabundant water shall be thrown 

 ■out of the vessels, we can seldom tell." 



Chronic or Passive Ascites is more commonly seen in old 

 ■dogs, and is usually associated with some old-standing 

 disease, either connected with the heart or large venous 

 trunks, in which some obstruction to the proper return of 

 blood is present, often originating in some morbid condi- 

 tion of the liver, spleen, lungs, or kidneys. In the dog it is 

 never the result of chronic peritoneal inflammation. 



"Active and passive dropsy," Watson observes, "resemble 

 each other in the result ; namely, in the collettion of serous 

 liquid in the circumscribed cavities and vacuities of the 

 body. They differ in the rate at which the collection 

 augments. 



" Iti the well-marked acute dropsies, the liquid is rapidly 

 effused in quantity much beyond the natural amount of 

 exhalation. In the well-marked passive dropsies the ex- 



