[ 3 8 9 3 
Experiment XII. 
Immediately after killing a dog, I tied up his jugular 
veins near the Jlernum , and hung his head over the 
edge of the table, fo that the parts of the veins 
where the ligatures were might be higher than his 
head. I looked at the veins from time to time, and 
obferved that they became tranfparent at their up- 
permoft part, the red particles fubfiding. I then 
made a ligature upon one vein, fo as to divide the 
tranfparent from the red part of the blood ; and, 
opening the vein, I let out the tranfparent part, which 
was dill fluid, but coagulated foon after. On pref- 
fing the coagulum , it was found to contain a little 
ferum. The other vein I did not open till after the 
blood was congealed, and then I found the upper 
part of the coagulum whitiih like the cruft in pleuri- 
tic blood 
It has been a very generally received, opinion that 
inflammation thickens the blood, and makes it more 
ready to coagulate. Nay, fome have gone fo far as 
to fay, that in thofe dilorders where the inflamma- 
tory cruft is feen, the blood is almoft coagulated 
* This is not the only animal that feemed to be in health, 
whofe blood had a cruft} I have feen it in others: whence I 
at firft fufpedted that merely keeping the blood fluid for a little 
time was fufficient to produce this appearance } but I altered 
my opinion, on feeing, that in the greateft number of animals 
it did not occur; nor is it commonly met with in the hearts of: 
thofe that die a violent death, though the blood remains longer 
fluid in fuch cafes than it does in the bafon where a fize 
appears.. 
even 
