I I°3 3 
CHAP. VI. 
An Examination of the Blood in Animals, 
W E cannot employ the Microfcope to 
any more ufeful Purpofe than to 
view the natural Courfe of the Blood within 
its Veifels, or examine the Contexture of-it 
when extracted from them : for the Prefer- 
vation or Refloration of the Health of Mam 
maybe greatly advantaged by fuch Enquiries. 
By feeing it within the Veffels, we may 
judge of the Situation, Dimenfions, Arrange¬ 
ment, and Ramifications of the Arteries and 
Veins through which it paffes, together with 
the general State of the Fluid, the Degree 
of its Impulfe, Progreflion, or Motion, and 
the Tendency or Direction of its Current 
pading through them. 
When taken from the Veffels, we can 
examine it more minutely, and obferve all 
the little Alterations that may happen in the 
Mixture, Size, Form, and Quality of the 
Particles compofmg its more folid or more 
fluid Parts. 
I fhall now fliew how the Microfcope may 
be employed in both thefe Ways; but think 
proper to premife a fhort Account of th q Blood 
itfelr, fince our Knowledge of that will the 
better enable us to make a right Judgment 
when we come to fee it circulate. 
CHAP. 
A 
/ 
