GENERAL USES OF THE CIRCULATION. 183 



becoming again colorless in the sacro-vertebral angle, which 

 is a little more raised, and resuming its cruoric appearance 

 in the iliac veins, especially in the inner ones ; the clots in 

 the pulmonary veins are always very dark, on account of 

 their inclined position. By turning the corpse over, while 

 these clots are forming, their position is changed, and mixed 

 clots of an opposite composition obtained. 



It is plain how useful and important these facts may be, in 

 legal medecine, for instance, by deciding the position in 

 which a corpse has lain during 24 hours after death. They 

 are all the result of that singular property by which the 

 internal coat of the vessels prevents coagulation. 



This is not the only property of the vascular walls ; it is 

 observed that coagulation in the vessels produces a clot, but 

 little or no serum is found : this is owing to the fact that 

 when the arterial coats lose their properties as living tissues, 

 the fluid part of the blood predominates ; either because these 

 coats, being no longer living, cannot effect those natural 

 changes of absorption, etc. ; or because the separation of the 

 fibrine has left the other albuminous elements of the blood in 

 a state of composition favorable to their exudation, as occurs 

 in the living body, and, by a similar mechanism, in certain 

 forms of oedema and albummuria* 



