348 Dr. Thomson's Chemical Analysis 



shaken. Cases occurred in which bleeding was evidently in- 

 jurious; and when the number of cases multiplied, it became 

 evident that bleedinrr had jjot credit for proloncinsr life with- 

 out deservinfj it. x'or many who had not been bled were 

 observed to linger fully as long as those who had : in short, 

 it began to be believed that bleeding might be injurious in 

 cholera, and that there was no evidence of its being ad- 

 vantageous. 



During the latter end of February and the early part of 

 March, 1 got a number of specimens of cholera blood from 

 the cholera hospital in Albion-street. Patients were rarely 

 taken to this hospital till the disense had made considerable 

 progress. The cases were all well marked, and in several of 

 the specimens the blood had been drawn when a pulse could 

 scarcely be perceived at the wrist. 



The blood, when ic came to me, was in the usual tin-plate 

 cups employed in hospitals, into which it had been allowed to 

 flow. Its colour was always a very dark red, almost black ; 

 much darker than venous blood usually is ; and it did not 

 acquire a scarlet colour, as blood from a person in health does 

 when exposed to the air. It coagulated as usual, and separated 

 into serum and crassamentum ; but the serum was much less 

 in quantity than it usually is. It was always (except in one 

 instance) more or less tinged with colouring matter; often so 

 deeply as to rival the colour of the crassamentum itself. The 

 following table exhibits the specific gravity of various spe- 

 cimens of serum from different cholera patients. 

 Sp. Gravity. 



This was pure yellow serum. 



Very slightly tinged red. 



Very red. 



Very red. 



A very deep red. 

 A specimen, taken out of the cavities of the heart after death 

 was imperfectly coagulated. Being poured on a cotton cloth, 

 a very dark red liquid dropped through, the specific gravity 

 of which was 1-0938. 



I got a specimen of blood from the cerebral vessels of 

 another cholera patient after death : it was not coagulated ; 

 nor did it coagulate, though I allowed it to stand in an open 

 vessel for thirty-six hours. After standing at rest for thirty- 

 six hours, I observed that the uppermost portion was very 

 fluid and apparently watery ; and though it had a deep red 

 colour, it did not tinge a glass rod dipped into it. The por- 

 tion at the bottom was thick and viscid, and stained strongly, 

 sticking to everything like tar. The specific gravity of the 



uppermost 



