28 



EXPERIMENTS ON THE CIRCULATION 



Kx|iiTiinunts. 



1 

 2 

 3 



4 

 5 



Interval between the 



application of ligature and 

 dr.ith of till! aivmal. 



10 minutes. 

 30 minutes. 

 30 minutes. 



10 minutes. 

 6 minutes. 



3^ minutes. 

 1 hour. 



Composition of the urine 



as rocards the presence in it of 



albumen, lymph, or bluod. 



Slightly albuminous. 



Ditto. ditto. 



No urine in bladder ; uivter 



nut examined. 

 Highly albuminous. 

 Very highly albuminous, and 



si imc slight appearance of 



fibrine. 



Bloody. 

 Ditto. 



These experiments alone suffice to show that the 

 same kind of effusion does not necessarily and con- 

 stantly result from the existence of the same degree 

 of obstruction. It will be evident that this latter 

 constitutes but one of the conditions required to 

 cause the exudation of the more viscid portion of 

 the blood through the coats of its containing vessels. 

 A certain amount of impulse of the arterial blood 

 must always co-exist and co-operate with the ob- 

 struction, before that species of effusion can take 

 place. The activity of this force will of course be 

 proportioned to the rapidity and vigour of the ven- 

 tricular contractions ; and it is to the varied power 

 of the heart's action, at the moment of applying the 

 ligature, that I ascribe the different results met 



O ' 



with in the above experiments. I have throughout 

 invariably observed that the effects of an intense 

 degree of compression were chiefly to be expected 

 in those instances where the animal seemed to 

 recover moat speedily from the shock of the opera- 

 tion. 



