ITS COAGULATION. 195 



membrane of any frog. The contents of the colourless blood-cells 

 consist of an albuminous solution, in which there are suspended 

 extremely fine granules, together with a single, double, triple or 

 multiple nucleus, which may be either smooth or granular. Water 

 causes the corpuscles to swell, and renders the nucleus visible ; 

 the phenomenon is more marked if dilute acetic acid be used, 

 which gradually dissolves the cell-wall, and leaves the nucleus 

 exposed ; the endosmotic action of water induces a distinct mole- 

 cular motion in the granular contents of the cells. 



We know far less regarding the chemical nature of the different 

 constituents of the colourless blood-cells, than regarding that of 

 the red corpuscles. As we must notice cells of this kind more 

 fully in our remarks on " Pus/' we shall defer for the present 

 any further remarks on what is known on this subject. 



There are other morphological elements, as fat globules, 

 molecular fibrin, &c., which we shall notice when treating of the 

 serum. We make no remarks on the infusoria which some have 

 maintained that they have found in the blood, treating the subject 

 as a long-exploded error. 



The textureless fluid constituent of the blood is the inter- 

 cellular fluid, which, in the circulating blood, contains the fibrin in 

 solution, as well as the constituents of the serum ; hence, we first 

 proceed to the consideration of the fibrin, and the more so, since 

 from its separation from the blood in the form of the clot, it is 

 closely associated with the blood-corpuscles. As we have already 

 fully noticed the chemical nature of fibrin (see vol. i, pp. 348- 

 S64), we shall here direct our remarks, for the most part, to the 

 mechanical relations which are dependent on the spontaneous 

 separation of the fibrin from freshly drawn blood. We shall 

 therefore, now, principally notice the coagulation of the blood 

 and its results the clot and its different physical characters. 



We have already (see vol. i, p. 343) referred to the views that 

 have been advanced in reference to the cause of the spontaneous 

 coagulation of the fibrin ; we have only additionally to mention an 

 hypothesis recently put forth by C. Schmidt,* which is essentially 

 very similar to the opinion previously expressed by Schultz. 

 Schmidt believes that the fibrin becomes formed and separates in the 

 following manner : as the blood escapes from the circulation, an acid 

 albuminate of soda which is dissolved in it, becomes disintegrated 

 into its component parts in such a manner, that a less acid, neutral 

 or basic albuminate of soda remains dissolved, while the other 

 * Characteristik d. Cholera, u. s. w., S. 205. 



o 2 



