FROM THE INFECTED ORGANISM. 



most in favour at the present time, is the last. The 

 opinion seems generally held, that disease-germs, 

 like urea, uric acid, and other poisonous matters 

 present in the blood may be selected and separated 

 from the normal constituents of the circulating fluid 

 by the agency of cells situated external to the vessels, 

 and thus " eliminated " from the organism. But 

 there is no analogy whatever between non-living urea 

 and uric acid, and living disease-germs, while it is an 

 error to suppose that if fluid is discharged from the 

 blood the process is invariably due to the influence of 

 epithelial or other cells. The result is often, I believe 

 almost invariably, dependent upon other circum- 

 stances altogether. So far from the epithelium 

 taking an active part in the process, this structure is 

 often damaged and sometimes destroyed and stripped 

 off by the free escape of fluid from the blood, or 

 before any discharge has commenced to take place. 



The escape of the fluid is usually associated with a 

 highly distended state of the capillary vessels. There 

 have been stretching and consequent thinning of the 

 capillary walls in these cases. Even after death fluid 

 will transude through the capillary vessels which 

 have been involved, with undue readiness. This I 

 have frequently noticed in injecting the vessels of 

 persons who have died of cholera. Although the 

 fact has not been observed in every case, it has 

 occurred too often to be regarded as a mere accident, 

 and in many instances the phenomenon was so 



