BLOOD. 105 



If, upon the addition of water, the blood-corpuscles have 

 swelled to such a degree as to be imperceptible under the mi- 

 croscope, they may be restored to their pristine form by the 

 addition of a solution of sugar, of common salt, of nitrate of 

 potash, or of muriate of ammonia. Schultz^ explains this 

 phenomenon by the supposition that the capsule of the blood- 

 corpuscle is an organic structure, which is stimulated to con- 

 traction by the above solutions, but which is relaxed or ex- 

 panded by water. In confirmation of this view, he observes 

 that the hsemato-globulin is not precipitated by the action of 

 the sugar or salts. Schultz has also shown that when the 

 capsules have even fallen to pieces in the water, the addition 

 of a little tincture of iodine, diluted with water, will render 

 their fragments visible. 



The blood-corpuscles do not always present a regular num- 

 mular and flattened appearance; they are sometimes plicated 

 and bent in. 



The cause of this phenomenon is not known, but it is pro- 

 bably due to a contraction of the capsule at different points. 

 One of the most peculiar of these forms is that in which the 

 edge of the blood-corpuscle appears as if it were studded with 

 minute pearls. In the blood of a patient suffering from 

 Bright's disease, I found that nearly all the corpuscles had 

 undergone this modification. On the addition of a solution 

 of muriate of ammonia, the appearance it presented under the 

 microscope was very striking. I immediately made a counter- 

 experiment with my own blood, but it did not exhibit the 

 phenomenon in question. 



Ascherson^ has offered the following explanation of this 

 peculiarity in the form of the corpuscle, viz., that it is due to 

 the exudation of fat which exists in a fluid state in the blood- 

 corpuscle. 



In opposition to this view, it may be urged, that if each 

 individual corpuscle contained a separable portion of fat (how- 

 ever minute it might be), we should obtain in our analyses a 

 much larger quantity of fat than in reality we do. It is true 

 that the dried clot yields a larger proportion of fat than an equal 



■ Ueber die gehemmte und gesteigerte Auflosung der verbrauchten Blutbliischeu. 

 Ilufeland's Journal, April 1838, p. 18. 



^ Miiller's Archiv, 1840. Uebcr die Bedeutung der Fettstoffe. 



