The seeing Witness is little Madame de Staal (by no means Necker's Daughter, but a much cleverer), known as one of the sharpest female heads; she from the spot reports it to Madame du Deffand, who also is known to readers.

There is such a glimpse afforded here into the actuality of old things and remarkable human creatures, that Friedrich himself would be happy to read the Letter.
Duchesse du Maine, Lady of Sceaux, is a sublime old personage, with whom and with whose high ways and magnificent hospitalities at Sceaux, at Anet and elsewhere, Voltaire had been familiar for long years past.
[In--OEuvres de Voltaire,--lxxiii.

434 n, x.

8, &c., "Clog." and others represent THIS Visit as having been to Anet,--though the record otherwise is express.] This Duchess, grand-daughter of the great Conde, now a dowager for ten years, and herself turned of seventy, has been a notable figure in French History this great while: a living fragment of Louis le Grand, as it were.

Was wedded to Louis's "Legitimated" Illegitimate, the Duc du Maine; was in trouble with the Regent d'Orleans about Alberoni-Cellamare conspiracies (1718), Regent having stript her husband of his high legitimatures and dignities, with little ceremony; which led her to conspire a good deal, at one time.