of bloud being weaker, it will be apt to congeal thefooner, 
fo that at the latter end of the work you muft draw out the 
Quill oftefj and clear the paflage; if the Dog be faint-hearted, 
as many are, though fome ftout fierce Dogs will bleed 
freely and uninterruptedly , till they are convuls'd and dye. 
But to prevent this trouble, and make the experiment certain, 
you muft bleed a great Dog into a little one, or a Maftive in^ 
to a CutTy as I once try'd^and the little Dog bled out at leaft 
double the quantity of his own bloud, and left ihtMaflive 
dead upon the Table, and after hewasuntyed, he ran away 
and fliak'd himfclf^ as if he had been only thrown into water. 
Or clfe you may get three or four fcveral Dogs prepared in 
the fame manner ^ and when one begins to fail and leave off 
bleeding, adminifter another, and I am confident one Dog 
Will receive all their bloud, ( and perhaps more) as long as 
ir runs freely, till they are left almoft dead by turns : provided 
that you let Out the bloud proportionably, as you let it goe 
into the Dog, that is to livr. 
Thirdly^ i fuppofe the Dog that is to bleed out into difhes 
will endure it the better, if the Dogs that are to be adminis 
ttrcd to fupply his bloud, be of near an equal age, and fed 
alike the day before, that both their blouds may be of aneer 
ftrength and temper* 
There are many things I have obferved upon bleeding Dogs 
to death, which I have feen fince your departure from Oxford^ 
whereof I fliall give you a relation hereafter^ in the mean 
time fitice you were pleafed to mention it to the J{oyal Society, 
with apromife to give them an account of this experiment, 
I could not but take the firft opportunity to clear you from 
that obligation, ^c. 
So far ibis Letter s the prefcrJptions whereof having been 
carefully oblerv'd by thofewho were imployed to make the 
Experiment, have hitherto been attended with good fuccefsj 
and that not only upon Animals of the hmt Species (as two 
Dogs firft, and then two Sheep ) but alfo upon fome of very 
differing Species ( as a Sheep and a Dog ^ the former Emittingy 
t\\Q othtv 'E^ceiving.^ 
Note on'y; that inftead of a Quill, afmall crooked thin 
Pipe 
