rhe PREFACE, xvii. 
then make conhderable Advances, 
when many pall run to and fro^ 
and Knowledge pall be increafedt 
Dan. xii. 4. In the mean time, it 
would but ill become us in this our 
State of Uncertainty, to treat the 
Errors and Miftakes of others with 
Scorn and Contempt, when we can- 
not but be confcious, that we our 
felves fee Things but as thro a Glafs 
darkly., and are very far from any 
Pretenlions to Infallibility. 
As it has ever been of great Im- 
portance to the Welfare of Mankind, 
to make the beft Refearches they can 
into the Nature of our Bodies, fo 
have many eminent Perfbns, from 
time to time, made confiderable Dif- 
coveries therein. And as the animal 
Fluids move by Hydraulick and Hy- 
droftatical Laws, fo I have here made 
fome enquiry into the Nature of their 
a Motions 
