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II. An Account of the f Boo!^ entituled Commercium 
Epiftolicum Collinii 3c aliomm, De Analyfi 
promota 3 publifhed by order of the Royal-Society, 
in relation to the Difpute between Mr. Leibnitz and 
T)r. K eill, about the tfdjvht of Invention of the 
Method of Fluxions, by fome call’d the Differen- 
tial Method. 
S Everal Accounts having been publifhed abroad of thi3 
Commerc'urm, all of them very imperfed .* It has been 
thought fit to publifh the Account which follows. 
This Commerchm is compofed of feveral ancient Letters 
and Papers, put together in order of Time, and either co- 
pied or tranflated into Latin from fuch Originals as are de- 
scribed in the Title of every Letter and Paper ; a numerous 
Committee of the Royal-Society being appointed to examin 
the Sincerity of the Originals, and compare therewith the 
Copies taken from them, It relates to a general Method of 
refolving finite Equations into infinite ones, and applying 
thefe Equations, both finite and infinite* to the Solution of 
Problems by the Method of Fluxions and Moments. We will 
firft give an Account of that Part of the Method which con- 
fids in refolving finite Equations into infinite one-, and 
fquaring curvilinear Figures thereby, By Infinite Equati- 
ons are meant fuch as involve a Series of Terms con- 
verging or approaching the Truth nearer and nearer in infini- 
tum^ fo as ac length to differ from the Truth lefs than by any 
given Quantity, and if continued in infinitum, to leave no 
Difference. 
G g Dr, 
