<■( 204 ') 
* k’Foi 1 tasking liimfelfrhc firft I mentor of the Differential 
Method, he has reprefented that Mr- Newton at firfl ufed the 
Letter 0in the vulgar manner for the given Increment of x, 
which deftroys the Advantages of the Differential Method; 
but afeer the Writing of his Principles, changed o into x, fub- 
flitutihg x for dx. It lies upon him to prove that Mr. Newton 
ever changed o into x, or ufed x for dx, or left off the Ufe of the 
Letters. Mr. Newton, ufed the Letters in his Analysts written 
in or before the Years 1669, and in his Book of J^uadra- 
tures , and in his P rmcipia, Philo(ophi<z, and (till ufes it in the 
Very lame Senfe as at firfl, In his Book of Quadratures he 
ufed it in conjunction with the Symbol x, and therefore did 
not ufe that Symbol in its Room. Thefe Symbols 0 and x are • 
put'for things of a different kind. The one is a Moment, 
the other a Fluxion or Velocity as has been explained above. 
When the Letter * is put for a Quantity which flows uni- 
fOrtnly, the Symbol x is an Unit, and the Letter 0 a Moj 
ment, and xo and dx fignify the fame Moment. Prickt 
Letters never fignify Moments, unlcfs when they are multi- 
plied by the Moment 0 either expreft or underflood to make 
them infinitely little, and then the Re&angles are put for 
Moments. 
Mr. Newton doth not place his Method in Forms of Sym- 
bols, nor confine himfelf to any particular Sort of Symbols 
for Fluents and Fluxions. Where he puts the Areas of Curves 
for Fluents, he frequently puts the Ordinates for Fluxions, 
and denotes the Fluxions by the Symbols of the Ordinates, 
as in his Analysis. Where he puts Lines for Fluents, he puts 
any Symbols for the Velocities of the Points which deferibe 
the Lines, that is, for the firfl Fluxions ; and any other Sym- 
bols forth e Increafe of thofe Velocities, that is, for the fe- 
cortd Fluxions, as is frequently done in hi sPrincipidFhilcfo- 
phU. And where he puts the Letters xr, y , zl for fluents, he 
denotes their Fluxions, either by other Letters as p, q, r ; or by 
the fame Letters in other Forms as X, T,Z or x, y , k ; or by 
any 
