[ 403 . ] 
“ Teems to be the method nature takes to give 
** the blood time to coagulate!” As this observation 
Teemed to Tavour my fuipicion, I determined to make 
the experiment. 
Experiment XXI. 
Believing it would be Tuffieient for this purpofe, to 
attend to the properties of the blood, as it flows at 
different times from an animal that is bleeding to 
death, I therefore went to the markets, and attended 
the killing of fheep ; and having received the blood 
into cups, I found my notion verified. For I ob- 
ferved, that the blood, which came from the veffels 
immediately on withdrawing the knife, was about 
two minutes in beginning to coagulate ; and that the 
blood taken later, or as the animal became weaker, 
coagulated in lefs and lefs time ; till at laid, when 
the animal became very weak, the blood, though 
quite fluid as it came from the veffels, yet had hardly 
been received into the cup before it congealed. I 
have alfo varied the experiment, by receiving blood 
into different cups at different times, whilfl the 
animal was bleeding to death j and though the time 
taken up in killing the animal was not com- 
monly more than two minutes, yet I obferved, on 
comparing the cups, that the blood which ilfued lafl 
coagulated firft. I have obferved likewife, that the 
blood coagulates with a different appearance in pro- 
portion as the animal becomes weaker j that which 
follows the knife begins to coagulate in about two 
minutes ; it firfl forms a film or pellicle on the fur- 
face, which extends gradually through the whole 
F f f z blood. 
