. ( ll 4 ) 
to tell the World what it was ; and why in his Letter of May 
. 12. 1676 he defired Mr. Oldenhurgh to procure from 
Mr . Collins the Demonftration of Mr. Newtons Series for 
doing the fame t.hing ; and wherein his own Series differed 
from Mr. Newtons. For upon all thefe Confiderations there 
is Sl Sufpicion that Mr. Newton's Series for finding the Arc 
whole Sine is given, was communicated to him in England; 
and that in the Year 1673 he began to communicate ft as his 
own to fome of his Friends at Paris, and the next Year wrote 
of it as his own in his Letters to Mr. Oldenhurgh , in order to 
get the Demonftration or Method of finding fuch Series. 
But the Year following, when Mr. Oldenhurgh lent him this 
Series and the Series of Mr. Gregory and Six other Series, 
he dropt his Pretence to this Series for want of a Demonftra- 
tion, and took time to confider the Series lent him, and to 
compare them with his own, as if his Series were others 
different from thofe fent him ..And when he had found a 
Demonftration of Gregorys Series by a Tranfmutation of Fi- 
gures, he began to communicate it as his own to his Friends, 
at Paris , as he reprefents in the /Iff a Eruditorum for April 
1691. fag. 178, faying; Jam Anno 1675 compofitum habebam 
cpufculum ' Quadrat ur a Arithmetic a ah Anticis ah illo tempore 
leffum , &c. But the Letter by which he had received this 
Series from Mr. Oldenhurgh he concealed from his Friends, 
and pretended to Mr- Oldenhurgh that- he had this Series a 
Year or two before the Receipt of that Letter. And the 
next Year, upon receiving two of Mr. Newton's Series again- 
by one George Mohr , he wrote to Mr. Oldenhurgh in fuch a 
manner as if he had never feen them before, and upon Pre- 
tence of their Novelty, defired. Mr. Oldenhurgh to procure 
from Mr. Collins Mr. Newtons Method of finding them. If 
• Mr. Lethnitz thinks fit to obviate this Sufpicion, he in the 
firft Place to prove that he had Mr. Gregory's Series before he 
received it from Mr. Oldenhurgh, 
If 
! 
t 
