COAGULATION OF THE BLOOD. 531 



bustive process. That which may be superfluous, is either deposited in the 

 cells of Adipose tissue, or it is eliminated by the Liver, the Sebaceous follicles 

 of the Skin, and (in the nursing female) by the Mammary glands. How the 

 peculiar Phosphorizcd Fats of the Blood are formed, whether by the con- 

 tinuation of the azotized and phosphorized materials with ordinary fat, or 

 by the metamorphosis of albuminous matter, cannot be said to be yet de- 

 termined. 



699. When the Blood is drawn from the body, and left to itself, its organic 

 elements speedily undergo a new arrangement. The Fibrine coagulates, and 

 separates itself from the fluid in which it was previously dissolved ; and during 

 its coagulation it attracts the Red particles ; these are included in areolac or 

 meshes of the Clot, the substance of which has a tendency to assume a fibrous 

 arrangement ( 118) ; and they usually group themselves together in columnar 

 masses, resembling piles of money. The Coagulum or clot becomes dense, 

 in proportion to the amount of the Fibrine it contains ; and the Albuminous and 

 Saline matter still dissolved in the water are separated from it, constituting the 

 Serum. This separation will not occur, however, if the coagulation take 

 place in a shallow vessel; nor if the amount of Fibrine should be small, or 

 its vitality low. A homogeneous mass, deficient in firmness, presents itself 

 under such circumstances; though the solid part of this may pass into a state 

 of more complete condensation, after the lapse of a certain time. That the 

 coagulation is due to the Fibrine, and that the Red particles are merely passive 

 in the process, appears from several considerations. A microscopical exami- 

 nation of the Clot shows, that it has the same texture with Fibrine, when 

 coagulating by itself; the Corpuscles clustering together in the interspaces of 

 the network, and not being uniformly diffused through the whole mass. Their 

 Specific Gravity being greater than that of tf*e Fibrine, they are usually most 

 abundant at the lower part of the clot ; and the upper surface is sometimes 

 nearly colourless, especially when the coagulation has taken place slowly ; yet 

 this upper part is much firmer than the under, showing that the Fibrine alone 

 is the consolidating agent. This has been proved to demonstration by an 

 experiment of Miiller's. He placed the blood of a Frog, diluted with water 

 (or still better with a very thin syrup) on a paper filter, of sufficiently fine 

 texture to keep back the Corpuscles ; and the Liquor Sanguinis, having passed 

 through the filter completely unmixed with them, presented a distinct coagu- 

 lum, although from the diluted state of the fluid, this did not possess much 

 consistency. Owing to the more minute size of the Blood-discs of warm- 

 blooded animals, this experiment cannot be so readily performed with their 

 blood. The sole agency of the Fibrine in coagulation is very easily proved 

 in another way. If fresh drawn blood be continually stirred with a stick, the 

 Fribrine will adhere to it in strings during its coagulation ; and the Red parti- 

 cles will be left suspended in the serum, without the slightest tendency to 

 coagulate. Moreover, if a solution of any salt, that has the property of re- 

 tarding the coagulation (such as carbonate of potash or sulphate of soda), be 

 added to the blood, the Corpuscles will have time to sink to the lower stratum 

 of the fluid, before the clot is formed ; the greater part of the Coagulum is 

 then entirely colourless, and is found by the microscope to contain few or no 

 red particles. 



700. That the Coagulation of the Blood is not, as some have supposed, a 

 proof of its death, but is rather an act of vitality, appears evident from what 

 has been already stated ( 118) of the incipient organization which may be 

 detected even in an ordinary clot ; and still more from the fact that, if the 

 effusion of Fibrine take place upon a living surface, its coagulation is the first 

 act of its conversion into solid tissues possessing a high degree of vitality. It 

 is absurd to suppose that the Blood dies, in order to assume a higher form. 



