118 CIRCULATING FLUIDS: 



rating or impeding the coagulation, is exerted by sulphate of 

 lime, chlorate of potash, or iodide of iron.i 



According to Magendie and Hamburger, the coagulation is 

 accelerated by acetate of morphine. The former observer states 

 that water, a Avatery solution of sugar, the fluid of dropsy, 

 Seidlitz and Vichy waters, alcohol, ether, and mannite ; and 

 the latter, that decoctions of digitalis, and tobacco, solution of 

 tannin, iodine, solution of sugar, gum arable, starch, and fresh 

 urine, have a similar efi'ect.- 



ON THE CHEMICAL PHYSIOLOGY OF THE BLOOD. 



On the formation of the blood. 



The formation of the blood, and especially of the blood- 

 corpuscles, has been made a subject of careful and laborious 

 research by many of the best microscopic observers of the 

 present age, amongst whom we may enumerate the names 

 of SchultZj Baumgartner, Valentin, Reichert, Wagner, and 

 Schwann. 



[As the physiological details connected with this subject 

 belong strictly to the physiology rather than to the chemistry 

 of the blood, we shall content ourselves with a brief statement 

 of all that is known with any degree of certainty regarding 

 this obscure and intricate process. 



Capillary vessels are developed by the stellated union of a 

 certain set of blastodermic or germinal cells ; and no sooner 

 are capillary or other vessels formed, than a kind of blood is 

 found in them. The corpuscles of that blood difi'er from those 

 of the adult in being considerably larger, more spherical and 

 granular, and in containing a distinct nucleus. There is pro- 

 bably an external envelope. The granules unite or amalga- 

 mate, so as to form the coloured or clear part of the blood- 

 corpuscle, while the nucleus remains. See fig. 2.] 



Although much light has recently been thrown on the 

 formation of the blood-corpuscle in the embryo, we are still 



' Magendie observed that the coagulation is hastened by the addition of the chlo- 

 rides of potassium, sodium, ammonium, and barium ; of bicarbonate of soda, sulphate 

 of magnesia, Ijorax, nitrate of silver, iodide of potassium, and the cyanides of gold 

 and mercury. 



^ [A summary of Mr. Blake's experiments on the effects of various salts, &c. on the 

 blood, is given in Wilhanis's Principles of Medicine, page 99.] 



