THE BLOOD. 23 



termining, in doubtful cases, whether life has become extinct 

 or not. 



It is by no means difficult to establish the fact of the 

 coagulation of the blood in the vessels after death. If a vein 

 be opened, as in the ordinary operation of bleeding, in a 

 person who has just died, the blood will issue in a fluid state, 

 as in life ; but it will not leap forth in a stream. If a little 

 of the blood, thus procured, be preserved in a small glass, 

 we shall soon remark the occurrence of coagulation in it, 

 from which we shall know that the fibrin within the vessels 

 has not as yet assumed a solid form. If we repeat this 

 operation at the end of about eighteen hours, we shall obtain 

 only a small quantity of reddish serum, in which, on being 

 set aside for a time, no crassamentum will be found, the only 

 change occurring in this serum consisting in the subsidence 

 of the few red globules which were previously suspended in 

 it, and which now form, at the bottom of the glass, a loose 

 and powdery mass. By this experiment, which may be 

 repeated on several veins, and even on an artery, we have 

 clearly established the fact of the coagulation of the blood 

 within the vessels of the body, and therefore have ascertained, 

 in a manner the most satisfactory, that life is extinct. 



In some instances, the blood is said to remain fluid after 

 death : this statement is not strictly correct, as a careful 

 examination of such blood will always lead to the detection 

 of some traces of coagulation. To the subject of the fluid 

 condition of the blood after death, we shall have hereafter to 

 return, in treating of the pathology of the blood. 



When it is recollected that the heat of some climates, and 

 the laws and usages of other countries, compel the interment 

 of the dead a very few hours after decease, the importance 

 of this inquiry will become apparent ; and the value of any 

 sign which more certainly indicates death than those usually 

 relied upon in determining this question, will be more fully 

 appreciated. 



It cannot be doubted but that, from the insufficient nature 

 of the signs of death usually regarded as decisive, premature 

 interment does occasionally take place; and it is probable 



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