Of the Circulation of the Blood. 2 r' 
to one another, and joined together by a common 
membrane. 
Thefe firings or fibres appear through their whole 
length, to be made up of minute roundiih veficles ; and 
the blood veflels which intermix with them, afford an 
agreeable profpedt. 
The next experiment is gently to draw out a part of 
the frog’s gut, in order to apply the mefentery to the 
tnicrofcope, which is a moft beautiful and furprifing 
phenomena, when viewed through the microfcope, as 
Handing upon a table : but when applied to the folar 
apparatus before defcribed, you may view it in fo diftindt 
and fine a manner, that no words can defcribe the won¬ 
derful fcene which will then be prefented to your fight. 
The blood flowing through numberlefs veflels at one and 
the fame inftant, in fome one way, in others the quite 
contrary ; feveral of the veflels may be magnified an inch 
in diameter, and the blood globules rolling thro 5 them, 
will appear near as large as pepper-corns, and at the 
fame time in the minuteft veflels only Angle globules can 
find a paflage, and that not without putting on the form 
of oblong fpheriods ; here alfo in the moft inexpreflible 
manner, will be feen the pulfation and acceleration of 
the blood in the arteries, as before defcribed. 
As the animal grows languid, and near expiring, the 
blood in the arteries will be feen to flop fuddenly, and 
as it were feem to coagulate, and then run backwards 
for fome time; after which it will again recover its na¬ 
tural courfe, with a great deal of rapidity. 
A due confideration of thefe appearances, may poflibly 
account for the intermifiions, ftarts, and irregularities ia 
the pulfc of perfons near the point of death. 
C 3 Tig, 
