PROPERTIES OF THE BLOOD. 43 



matory crust on the blood in the cups, though a very dense one 

 on that in the basin. And again, although the blood in the 

 basin had been taken away some minutes before that in the 

 cups, yet it was later in being completely coagulated ; as was 

 evident on comparing them. 



I had an opportunity of repeating the experiment in the 

 evening; for the symptoms of inflammation seeming equally 

 violent, it was thought proper by the physicians who attended 

 her to take away more blood ; which was done by opening the 

 same orifice, when three teacups were nearly filled, and set in 

 the same place ; and it was observed, that the first had a crust, 

 though not so thick a one as in the first bleeding; but the 

 other two cups were without this appearance, though the blood 

 had flowed into them even more quickly than into the first. 1 



EXPERIMENT XX. 



A gentleman, who laboured under an inflammatory com- 

 plaint, had about nine ounces of blood taken from his arm. 

 This quantity was divided into four portions ; the first was re- 

 ceived into a cup, and was in measure little more than an 

 ounce ; the second into a basin, to the quantity of two ounces ; 

 the third into a cup, which held one ounce ; and the fourth 

 into a basin, to the quantity of three ounces. Each vessel 

 was immediately placed upon the window ; and it was observed 

 that the blood in the first was latest in coagulating, and had a 

 crust over the whole surface ; that in the second had a crust 

 only upon a part of its surface; but that in the third and 

 fourth had none, and manifestly coagulated before either of the 

 other two. 



Now, since in these experiments the blood in the first cups 



1 As this experiment seems contradictory to some mentioned hereafter, in the last 

 cups being filled rather sooner and yet coagulating sooner, which might be suspected 

 to be owing to the vessel's acting more strongly at the latter part of the operation 

 than at the beginning ; it is therefore necessary to observe, that the difference in this 

 experiment appeared to be only owing to a difference in the size of the orifice, for 

 when the ligature was first removed, the old wound was not so much torn open as it 

 was afterwards, when it was more enlarged in order to hasten the evacuation. But 

 it did not, in the beginning of the operation, trickle down the arm as in Exp. xxvn, 

 where the size of the orifice was not enlarged from the first, and yet in proportion as 

 the operation advanced, the velocity of the blood increased ; which was thence con- 

 cluded to be owing to ail increased action of the blood-vessels. 



