44 EXPERIMENTS ON THE CIRCULATION 



small healthy rabbit, the artery was eeen to pnss 

 obliquely behind it, rendering it very difficult to 

 isolate the former vessel. A thread was passed 

 around both, and tied so as to enclose both within a 

 loose loop. Eight hours afterwards, the animal was 

 alive and well. At the end of twenty-four hours, I 

 found it dead and cold. The left kidney was much 

 enlarged ; it was enveloped in a distinct cyst, appa- 

 rently formed of the surrounding cellular tissue, 

 which had been infiltrated with blood and lymph. 

 Except at one point, where the kidney had been 

 slightly scratched, there was no adhesion between 

 that organ and its investing membrane ; in fact, 

 they were separated from each other by a small 

 quantity of serous fluid. After reflecting this tunic, 

 an inner one (which I imagined to be the proper 

 capsule) appeared, and, like the former, could be 

 detached from the surface of the gland : thereby 

 proving satisfactorily the real existence of a second 

 membrane. The bladder contained about a drachm 

 of clear urine, which was moderately but distinctly 

 albuminous. 



Exp. 12. A precisely similar operation was per- 

 formed on a rabbit of the same size, the vein alone 

 being included in the loop; it died at the end of 

 two days and a half. The left kidney was sur- 

 rounded by a cyst similar to that met with in the 

 last experiment ; it adhered slightly at one or two 

 points to the capsule ; the latter could be stripped 

 off the kidney, and the separate existence of the two 

 membranes thus manifested. The external surface 

 of the gland presented three or four white spots, 



