As for business, I think I can trust you to yourself; but I wish I could say as much for you with regard to those exterior accomplishments, which are absolutely necessary to smooth and shorten the way to it.  Half the business is done, when one has gained the heart and the affections of those with whom one is to transact it.  Air and address must begin, manners and attention must finish that work.  I will let you into one secret concerning myself; which is, that I owe much more of the success which I have had in the world to my manners, than to any superior degree of merit or knowledge.  I desired to please, and I neglected none of the means.  This, I can assure you, without any false modesty, is the truth:  You have more knowledge than I had at your age, but then I had much more attention and good-breeding than you.  Call it vanity, if you please, and possibly it was so; but my great object was to make every man I met with like me, and every woman love me.  I often succeeded; but why?  By taking great pains, for otherwise I never should:  my figure by no means entitled me to it; and I had certainly an up-hill game; whereas your countenance would help you, if you made the most of it, and proscribed for ever the guilty, gloomy, and funereal part of it.  Dress, address, and air, would become your best countenance, and make your little figure pass very well.

If you have time to read at Hanover, pray let the books you read be all relative to the history and constitution of that country; which I would have you know as correctly as any Hanoverian in the whole Electorate.  Inform yourself of the powers of the States, and of the nature and extent of the several judicatures; the particular articles of trade and commerce of Bremen, Harburg, and Stade; the details and value of the mines of the Hartz.  Two or three short books will give you the outlines of all these things; and conversation turned upon those subjects will do the rest, and better than books can.

Remember of all things to speak nothing but German there; make it (to express myself pedantically) your vernacular language; seem to prefer it to any other; call it your favorite language, and study to speak it with purity and elegance, if it has any.  This will not only make you perfect in it, but will please, and make your court there better than anything.  A propos of languages:  Did you improve your Italian while you were at Paris, or did you forget it?  Had you a master there? and what Italian books did you read with him?  If you are master of Italian, I would have you afterward, by the first convenient opportunity, learn Spanish, which you may very easily, and in a very little time do; you will then, in the course of your foreign business, never be obliged to employ, pay, or trust any translator for any European language.