( i%7 ) 
mult a volumina jpiifia de his rebus edit a. JVuAre tibi par iter ac 
clarijfimis viris Newtono ac Collinio gratias a^o, qui nos parti- 
cipes tot meditationum egregiarum effevcluifiis . And towards the 
End of the Letter, after he had done with the Contents of 
Mr Newtons Letter, he proceeds thus. Ad alia tuarum Lite - 
rarum venio qttoe doclijfimus Collinius communicare gravatus non 
e(l. Vellem adjecifiet appropinquationis Gregorianse linearis de~ 
monftrationem. Fait enim his certe fiudiis promovendis aptijfimus. 
And the Anfwerof Mt-Tfchurnhaufe, dated Sept. 1. 1676, after 
he had done with Mr. Newtons Letter about Series, concludes 
thus. Similia porro quot in hue re pr&ftitit eximius Hie Geometra 
Gregorius vntmorAndA certe funt. Et quidem optime fam<e ipfius 
confulturi, qui ipfius relitla Manufcripta Luci publics ut exponantur 
eperam navabunt. In the firft Part of this Letter, where 
Mr . Tfchurnhaufe fpeaks of Mr. Newtons Series, he faith that 
he looked over them curforily, to fee if he could find the Se- 
ries of Mr. Leibnitz, for fquaring the Circle or Hyperbola. If 
he had fearched for it in the Extra&s of Gregory 's Letters he 
might have found it in the Letter of Felr. 15. 1671. above- 
mentioned. For the MS. of thofe Extra&s with that Letter 
therein is (till extant in the Hand-Writing of Mr. Collins. 
And tho’ Mr Leibnitz had now received this Series twice 
from Mr. Oldenburgh, yet in his Letter of Augu/lzj. 1676. he 
lent it back to him by way of Recom pence for Mr. Newtons 
Method, pretending that he had communicated it to his 
Friends at Paris three Years before or above; that is, two 
Years before he received it in Mr. Oldenburgh' s Letter of April 
1 5 1675- 5 at which Time he did not know it to be his own, 
as appears by his Anfwer cf May to. 1675 above-mentioned. 
He might receive this Series at London , and communicate it 
to his Friends at Laris above three Years before he fent it back 
to Mr. Oldenburg : but it doth not appear that he had the 
Demonflration thereof fo early. When he found the De- 
monftration, then he compos’d it in his Opufiuhm, and 
commu icated that alfo to his Friends ; and he himfelf has 
Hh 4 told 
