Arnold on Newton's anagram

Newton's anagram on his method to solve differential equations is contained in his letter to Leibniz dated October 24, 1676, as described here

At the end of his letter Newton alludes to the solution of the "inverse problem of tangents," a subject on which Leibniz had asked for information. He gives formulae for reversing any series, but says that besides these formulae he has two methods for solving such questions, which for the present he will not describe except by an anagram which, being read, is as follows, "Una methodus consistit in extractione fluentis quantitatis ex aequatione simul involvente fluxionem ejus: altera tantum in assumptione seriei pro quantitate qualibet incognita ex qua caetera commode derivari possunt, et in collatione terminorum homologorum aequationis resultantis, as eruendos terminos assumptae seriei."

You can read the anagram in the published letter:

5accdæ10effh11i4l3m9n6oqqr8s11t9y3x: 11ab3cdd10eæg10ill4m7n6o3p3q6r5s11t8vx, 3acæ4egh5i4l4m5n8oq4r3s6t4v, aaddæcecceiijmmnnooprrrsssssttuu.

as well as the translation of the latin text:

"One method consists in extracting a fluent quantity from an equation at the same time involving its fluxion; but another by assuming a series for any unknown quantity whatever, from which the rest could conveniently be derived, and in collecting homologous terms of the resulting equation in order to elicit the terms of the assumed series".

A curiosity: the anagram is flawed, there are two i's too few and one s too many. Errare humanum est.

The two anagrams (first and second) are in the same letter of Oct 24, 1676 to Leibniz.

An insert of the second and more rare is here:

and for the whole letter go here - lines -8, -7 and -6.