C i70 ) 
are made ufe of to prove the Pfoporidoii, or 
any Miftakes in the Reafonings from the Experi- 
ments made to confirm it, he ufhs other Mediums 
to prove his AfTertions ^ ; and without any Regard to 
what others had faid on that Subjedt, brings new Argu- 
ments, which the Reverend and Learned Dr. Clark 
has fully anfwered in his fifth Letter to him. Mef- 
fieurs John BernoulliyW olfius^ Her m annus ^2x16. others, 
have follow’d and defended Monfieur Leibnitz's Opi- 
nion, and in the fame manner, fo that what is an An- 
fwer to him, is fo to them. 
Boknns (Profefibr at Badua) has adfed after the 
fame manner in the experimental Way, making fbme 
Experiments to defend Monfieur Leibnitz's Opinion,, 
without having Ihewn thofe to be falfe. which are made 
ufe of to prove the contrary ^ ; and now lately, an in^- 
genious Profeffor abroad (who was of the Opinion 
commonly receiv’d, and in his Writings had demonflra- 
ted it in the ufual way confirming it with the commom 
’Experiments made in that Cafe) happening to make 
fome Experiments like thofe of Bolenus, has drawn- 
Conclufions from them to fliew the Force of moving 
Bodies to be proportionable to the Square of their Ve- 
locity ; and being wholly come over to that Opinion,, 
endeavours to deduce it from Phyfical Principles. 
As there can hardly be faid any thing new, or bet- 
ter than has been faid, to fhew the Force abovemeh- 
tion’d to be proportionable to the Mafs multiplied in- 
to the Velocity ; I only repeat here the Subflancc 
of what others have laid, and make fome old Experi- 
ments over, again ; but then I confider fome Circum- 
». Afta Emdit. ad ann. 1686. p. 162. ^ Polenus de Caftellis, p. 56,. 
57j &,c. ' Gvavcfande Imroduitio, Vol. I. No. 132, 
ftances. 
