THE BLOOD. 30 



Lastly, to see whether the specific gravity of the red globules 

 was increased, I proceeded as follows : 



EXPERIMENT XVIII. 



I poured into a phial C, a portion of the serum of the blood 

 which had no crust ; and likewise into another D, a second 

 portion of the same serum. I then added to C a teaspoonful 

 of the same serum, loaded with red particles from the blood 

 which had an inflammatory crust. And into D, I poured a tea- 

 spoonful of the same serum, loaded with the globules of that 

 blood which had no crust. In viewing these, I could not ob- 

 serve that the globules of the blood which had an inflammatory 

 crust subsided sooner than those of the blood which had none : 

 whence I inferred, that the specific gravity of the red particles, 

 or globules as they are called, is not increased in those cases 

 where the crust appears. And, therefore, since that inflam- 

 matory crust or size seems neither owing to the serum's being 

 attenuated, nor to an increased specific gravity in the red par- 

 ticles, it probably depends solely upon a change in the eoagu- 

 lable lymph. And what seems farther to confirm this inference, 

 in none of these experiments did the red particles subside from 

 the surface of the serum in twenty minutes, though, where the 

 crust appears, they subside from the surface of the blood in 

 half that time ; so that the whole mass of blood seems to be 

 thinner than the serum alone ; or, the coagulable lymph seems 

 to be so much attenuated in these cases, as even to dilute the 

 serum, which at first sight appears a paradox. 



May we not, therefore, conclude, that in those cases where 

 the inflammatory crust appears, the coagulable lymph is thinner, 



healthy gelding 1035. In both trials with the blood of the horse, the 

 serum first exuding from the clot, the serum last exuding from the clot, 

 and the serum obtained from the buffy coat, by pressure through a linen 

 bag, were all ascertained to be of the same specific gravity, con- 

 trary to what might have been expected from the observations of 

 Thackrah and Gendrin. The serum was in every instance filtered be- 

 fore it was weighed, and its specific gravity noted at a temperature of 

 60. Mr HunterJ found that the serum of blood from a person with an 

 inflammatory complaint, and serum of blood in a case not inflammatory, 

 were nearly the same respecting coagulation and the quantity of serosity, 

 or matter not coagulable by heat. The coagulating point of serum varies 

 with its proportion of albumen. See Notes in, g, xvn, and LII. 



' Works, edited by Palmer, iii, 51. 



