BLOOD. 325 



The second venesection in the 3d case was ordered at a 

 time Avhen the urine was less albuminous than it had been : the 

 third was prescribed after a considerable interval, and when the 

 urine contained no albumen. 



j3. Cholera. 



The researches of trust-worthy observers have shown that 

 the blood in cholera exhibits the following peculiarities. The 

 quantity of water is decreased, and consequently there is an 

 increase in the amount of solid constituents arising, in all pro- 

 bability, from the watery alvine evacuations ; the amount of 

 fibrin, as well as the alkaline reaction, is diminished, and urea 

 is found in the serum. The search after this substance has not 

 always been successful, but its presence has been clearly shown 

 by Rainy, 1 O^Shauglinessy,^ Marchand,^ eind myself. 



The following are the leading physical characters of the blood 

 in this disease. It appears to be thicker than usual, and either 

 forms a soft, friable clot, or else coagulates very imperfectly. 



Wittstock has made a careful analysis of the blood during 

 cholera. In its external characters it resembled healthy blood : 

 the clot was of a scarlet red colour on the surface, but darker 

 than usual in the interior. 



His analysis gave the following results: serum 36-55, clot 63*5^. 

 The specific gravity of the serum was 1-0385, and 100 parts 

 left 13-75 of solid residue. The clot, when treated with ab- 

 solute alcohol, left a residue of 31|^; the alcohol took up solid 

 crystalline, and thin fluid fat, chlorides of sodium and potassium, 

 lactates of soda and ammonia, extract of flesh, and traces of 

 phosphate of lime. By Avashing the clot, 6^ of fibrin were ob- 

 tained. Hence, if we consider the fluid of the clot to be serum, 

 we have the composition of this blood expressed as follows : 



Water .... 740-00 



' London Medical Gazette, Jan. 1838. 



» Ancell's Lectures on the Blood. The Lancet, 1840, p. 840. 



^ Poggendorf's Annalen, vol. 49, p. 328. 



