can assure you, is not more contrary to good manners than to good sense:
but endeavor rather to get all the good you can out of them; and
something or other is to be got out of everybody. They will, at least,
improve you in the German language; and, as they come from different
countries, you may put them upon subjects, concerning which they must
necessarily be able to give you some useful informations, let them be
ever so dull or disagreeable in general: they will know something, at
least, of the laws, customs, government, and considerable families of
their respective countries; all which are better known than not, and
consequently worth inquiring into. There is hardly any body good for
every thing, and there is scarcely any body who is absolutely good for
nothing. A good chemist will extract some spirit or other out of every
substance; and a man of parts will, by his dexterity and management,
elicit something worth knowing out of every being he converses with.

As you have been introduced to the Duchess of Courland, pray go there as
often as ever your more necessary occupations will allow you. I am told
she is extremely well bred, and has parts. Now, though I would not
recommend to you, to go into women's company in search of solid
knowledge, or judgment, yet it has its use in other respects; for it
certainly polishes the manners, and gives 'une certaine tournure', which
is very necessary in the course of the world; and which Englishmen have
generally less of than any people in the world.

I cannot say that your suppers are luxurious, but you must own they are
solid; and a quart of soup, and two pounds of potatoes, will enable you
to pass the night without great impatience for your breakfast next
morning. One part of your supper (the potatoes) is the constant diet of
my old friends and countrymen,--[Lord Chesterfield, from the time he was
appointed Lord-lieutenant of Ireland, 1775, used always to call the Irish