THE BLOOD. 19 



however, this coagulation, as already stated, proceeds much 

 more slowly; and thus time is allowed to the globules to 

 follow this impulse of the law of gravity to such an extent, 

 as that they fall a certain distance, about the sixteenth of an 

 inch, usually, below the surface of the fibrin before its com- 

 plete coagulation averts their further progress ; and a portion 

 of which is thus left colourless, which constitutes the buffy 

 and so called inflammatory crust of the blood. But there 

 are other considerations to which it is necessary to attend, 

 and which contribute to the formation of the buffy coat. 



One of these is the greater relative amount of fibrin which 

 inflammatory blood contains. 



A second is the increased disposition, first pointed out by 

 Professor Nasse, which the red corpuscles have in inflam- 

 matory blood to adhere together and to form rolls, and the 

 consequence of which is that they occupy less space in the 

 clot. 



A third additional consideration, to which it is necessary 

 to attend, in reference to the formation of the inflammatory 

 crust, is the density of the blood, which bears no exact 

 relation to the amount of fibrin, but depends rather upon 

 the quantity of albumen which it contains. * The greater the 

 density of the blood, the longer would the globules take to 

 subside in that fluid; and the less its density, the shorter 

 would that period be. Now inflammatory blood is usually of 

 high density, while with that of feeble vitality, the reverse 

 obtains. Thus were it not for the fact, that in blood in the 

 first state, coagulation is slow, and in the second quick, the 

 blood of weak vital power would be that in which, a priori, 

 we should expect to see the buffy coat most frequently 

 formed ; but the much greater rapidity in the coagulation of 

 the blood more than counterbalances the effect of density. 



The blood, then, may be so dense, that although at the 

 same time it coagulates very slowly, yet no inflammatory 

 crust be formed, the patient from whom the blood is extracted 



* It has been remarked, that in alburninuria, in which a considerable 

 portion of the albumen of the system passes off with the urine, the blood 

 possesses a very feeble density. 



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