( ) 
Ip, the fame Letter he has told us that he had this Method 
above Nine Years before he publifhed it, and it follows from 
thence that he had it in the Year 1675 or before. Andyec 
its certain that he* had it not when he wrote his Letter to 
Mr. Oldenburgb dated Aug. 17* *676, wherein he affirmed 
that Problems of the Inverfe Method of Tangents and ma- 
ny others, could not be reduced to infinite Series, nor to 
Equations or Quadratures.. It lies upon him therefore, in 
point of Candor, to tell us what he means by pretending to. 
have found the Method before lie had found it- 
We have fhewed that Mr. Leibnitz, in the End of the Year 
1676, in returning home from France through England and 
Flolhnd, was meditating how to improve the Method of 
■Skfuts-i or Tangents, and extend it to all forts of Problems, 
and for this. end propofed the making, of a genera Table 
of Tangents; and therefore had not yet found out the trup 
Improvement. But about- half a Year after, when he was 
newly fallen upon the true Improvement, he wrote Back > 
Clarifs. Slufii MethoJum T angentium nondum :jje ab(oluUm tele - 
berrimoNemoho ajfentior. Et jam A MlfLTO ' “ 
PO RE rem Tavgentium gener alius trattavi, Jcilicet pci diffe- 
rent ias Ordinatarum. W hich is as much as to fay that he had 
this Improvement long before thofe Days. It lies upon him, 
in point of Candor, to make us underfiand that he preten- 
ded to this Antiquity ofhis Invention wuh fome other De- 
sign than to rival and fupplant Mr. Newton, and co us 
believe that hehad the Differential Method before Mr. .New- 
ton explained it to him by bis Letters of June 1 3. and Ociob 
za. 167 6, and before Mr. Oldenburgb Lent him a Copy ( 5 b 
Mr Newtons Letter of Decern 10. i 67 x concerning it. 
The Editors of the Atfa Eruditorum m June i'6$6 in gi- 
ving an Account of the two firft Volumes of tire Mathema- 
tical Works of Dr. Wallis', . wrote thus, in the Style of 
Mr. Leibnitz. Cater urn ipfe Newtonus, n °\ minus 
qtam~ fracUris in rem Mathematics mentis infigms, police & 
