[ 23 ] 
but little from the proportion of the velocities ac- 
Whence 1 fhould apprehend it clearly follows ; 
that the impreffions made in loft bodies, by hard ones 
striking upon them, do vary from each other, ac- 
cording to the degree of cohelion in the refpedtive 
foft bodies ; and that the impreffions would be in 
exadt proportion of the velocities, could their form 
be perfectly retained by bodies quite void of cohe- 
iion. 
Nothing, however, being more evident to me 
than that a&ions ought to be meafured by their 
effects, and at the fame time fully depending on the 
accuracy of the experiments, I am determined to 
reft this important point entirely upon them. Shall 
not, therefore, attempt any illuffiation in the ma- 
thematical way, left, by too far indulging a favourite 
opinion, I fhould bewilder myfelf in intricate cal- 
culations. Much lefs fhall I endeavour to eftablifti 
my do&rine on metaphyficai principles, which feem 
to me in themfelves too obfeure, to throw any clear 
light on fubjedts of this nature. 
Received 
