Judging from various symptoms, I could guess this MS.

to have been much about, in the English Aristocratic Circles of that time; and to have, in some measure, given said Circles their "Idea" (as they were pleased to reckon it) of that wonderful and questionable King:--highly distracted "Idea;" which, in diluted form, is still the staple English one.
By the label, DEMON NEWSWRITER, it is not meant that the Author of this poor Paper was an actual Devil, or infernal Spiritual Essence of miraculous spectral nature.

By no means! Beyond doubt, he is some poor Frenchman, more or less definable as flesh-and-blood; gesturing about, visibly, at Berlin in 1752; in cocked-hat and bright shoe-buckles; grinning elaborate salutations to certain of his fellow-creatures there.
Possibly some hungry ATTACHE of Milord Tyrconnel's Legation; fatally shut out from the beatitudes of this barbarous Court, and willing to seek solacement, and turn a dishonest penny, in the PER-CONTRA course?
Who he is, we need not know or care: too evident, he has the sad quality of transmuting, in his dirty organs, heavenly Brilliancy, more or less, into infernal Darkness and Hatefulness; which I reckon to have been, at all times, the principal function of a Devil;--function still carried on extensively, under Firms of another title, in this world.
Some snatches we will give.

For, though it does not much concern a Man or King, seriously busy, what the idle outer world may see good to talk of him, his Biographers, in time subsequent, are called to notice the matter, as part of his Life-element, and characteristic of the world he had round him.

Friedrich's affairs were much a wonder to his contemporaries.