muft needs coagulate by the way and afterwards caufe fomi 
mortal palpitation; they forefee an accident which never haps 
lied to us, and againft which I defire no other fecurity than 
the experience we have had of all the animals hitherto em- 
ploy’d by us, which are ftill living. 
Others who have either been witneffes of fome of our 
Transfufions,or have underftood thefame from credible re- 
lators, difpute not the pofiibility of the thing 5 but yet not to 
authorize appears new, they fay 5 That whatfoever care and 
caution be uf*d in the Transfufion,it can never be pra&if'd up- 
on Man with, fuccefle; and thefe are their principal Rea- 
fonsv 
Firft, The blood of a hound, and the blood of a difeafed 
body having qualities very different, the one being pure, the 
other impure, a perfect mixture thereof cannot be effected j 
they are two contraries, which will be at perpetual fewd, the 
iffue whereof can be no other but the ruine and deftrudion ojf 
thefubje&on whom the experiment is attempted: I wifh 
thofe that difeourfe thus , firft underftood but what they en- 
deavour to perfwade others of; and that they would explains 
to us what artifice they fancy in the Veins and Arteries, to 
give paffage to one fort of blood & exclude another at the 
fame time. For my part I confefle I cannot comprehend 
why the continual circulation and rarefadion made in the 
heart by the heat of its Ventricles;, are not more than fufficient 
to make a perfecft mixture there of thefe two forts of bloody 
the difficulty feems the greater in regard experience appears to 
flatter me into a contrary opinion. For having a few dayes 
agoe fyrirg’d about a quarter of a pinte of Milk into the veins 
of an Animal, and having opened the fame fome time after, 
we found the Milk fo perfedly mixt with the whole fubftance 
of fheblood, that there was not any place wherein appear'd 
the leaft footftep of the whitenefsot Milk, and all the Blood 
was generally more liquid and lefs apt to coagulate. 
The fecond Obje&ion of the fame Author is. That fliould 
the pure Blood mingle with the impure, yet it would not 
long;' 
