IN THE KIDNEY. 25 



the circulation through the gland entirely under our 

 command, but are, at the same time, enabled to 

 isolate and confine the secretion, and thus prevent 

 the possibility of error in examining the composition 

 of the latter. Moreover, the recent discoveries of 

 my friend Mr. Bowman, by clearing away the mys- 

 tery which had previously surrounded the Mal- 

 phigian bodies, have made us well acquainted with 

 the minute anatomy of the kidney, and have thereby 

 enabled us more clearly to understand the mechanism 

 of the process. 



Having obtained all that I expected from ob- 

 structing the return of blood through the renal vein, 

 I was anxious to ascertain the effect of directing, 

 with different degrees of rapidity, an increased flow 

 of blood to the vessels of an organ previously 

 healthy ; the passage of this blood being unimpeded 

 by any artificial obstacle, and the organ itself being 

 untouched. After some unsatisfactory trials, I at 

 length obtained results precisely similar to those met 

 with in the former series after venous obstruction. 



Although the same general effects were produced 

 in all the experiments, it will be more advantageous 

 to consider them as arranged under two divisions. 



The first, containing twenty experiments, in all 

 of which some artificial impediment obstructed the 

 flow of blood through the vein. 



The second, comprising fourteen experiments, in 

 which an increased determination of blood was di- 

 rected to one or both kidneys, without any artificial 

 obstacle being opposed to its free return. 



