OF THE FLUIDS. 79 



OF THE FLUIDS. 



71. The fluids, or the humours* of the human body, are 

 contained in the solids, and penetrate all their parts. They 

 are composed of molecules, coming from without for the sup- 

 port of the body, and of those which are detached from it to 

 be rejected. Their fluidity is owing, not only to caloric and 

 water, like that of fluids foreign to the organization, but like 

 their composition, it depends upon the vital action. The fluids 

 differ from each other, one being gaseous, another vaporous, 

 and a third a liquid more or less flowing; they also differ in 

 colour; their composition too varies, but it is peculiar to them, 

 and can not be imitated by art. 



The fluids may be divided into three kinds, 1st, the blood, a 

 central mass, to which flow, and from which emanate all the 

 others; 2d, the humours which go to the blood from without; 

 3d, those which emanate from it. 



72. The blood is a liquid of a red colour, and of a peculiar 

 odour; it has a nauseous and slightly saline taste; its tempera- 

 ture is that of the body, of which it is even the warmest por- 

 tion; it is viscid to the touch; its specific gravity is about 105, 

 water weighing 100. It is contained in the heart, and san- 

 guiferous vessels. Its quantity in the adult is considerable, but 

 variable. This quantity has been very differently estimated, 

 varying from eight or ten pounds, to eighty or a hundred. 



73. Microscopic observers have made the following ob- 

 servations upon this fluid: the blood is composed of a serous 

 vehicle in which red microscopic globules, are held in suspen- 

 sion; these bodies have been generally considered, either as 

 spheres, marked with a luminous point in the centre, or as be- 

 ing pierced and consequently of ao annular form. Hewson, on 

 the contrary, conceived the red particles of the human blood to 

 be lenticular. The important observations of Messrs. Prevost 

 and Dumas and my own, have given the same result. Mr. 

 Home, like Dr. Young, considered the flattening as subsequent 



* See Plenck. Hygrologia corporis humani Chaussier. Table synoptiquc 

 des humeurs. 



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