Your letter of Feb. 19. was ten days on it’s passage to me, and this followed by an interval of six days between the arrival & departure of our mail, leaves but 6. days for this to reach you within the three weeks limited for your departure. I am sorry to learn that the state of your health is such as to oblige you to seek it’s repair in other countries, and with pleasure furnish you such letters as may assist in alleviating your peregrinations. supposing the National Museum, and National garden at Paris would be the most interesting objects for you, I inclose a letter for the Count de Lacepede at the head of the former, and M. Thouin who has the direction of the latter. I have not added letters for Dupont and Humboldt, because I am sure you are personally acquainted with them, and they can make you known to such of the literary circle as you may chuse. mr Crawford, even without a letter, would have been your patron ex officio. you ask my opinion of the best summering place. Geneva is that of the English, and affords very learned society. I inclose a letter to mr Pictet whose eminence is known to you. I do not know him personally, and altho’ our correspondence was only in the exchange of a letter or two, yet it was on a matter interesting to him, and I am sure he will recieve the letter I address to him with attention. but I should prefer Montpellier for the summer; for altho’ in a Southern part of France it is very elevated in it’s situation, open to all the winds, has a beautiful and extensive public garden, bowers, baths, and a good literary society. I give you a letter to Dr Gouan the patriarch of the literati there, and of the place, and who does it’s honors to strangers with great kindness. he has written in Botany and Medecine.1 on your way Southwardly you will visit Marseilles of course, a delightful residence and affording good society in science. my old friend Cathalan is but a merchant, but he knows every body and can make you known to them.

for Florence where you propose to make some stay, I give you a letter to Mr Fabbroni, well known to the men of science of Europe. he is of an Agricultural society of Florence, and has written in that line; he is also at the head of the public library there. you will surely from thence visit Pisa, celebrated for it’s fine situation, salubrity, for it’s academy and learned society. there my friend Mazzei (if alive, for he is upwards of 80.) will make you known. he is a furious republican, affectionately attached to America, and will be delighted with what you will tell him of the successes of our two last campaigns. he is author of the Recherches politiques et historiques des E.U. d’Amerique.2 should you visit Leghorn also from Florence the letter to Appleton will be of service.—I will add an observation worthy the notice of every traveller. when one has to go from one place to another at a distance, never think of the direct road, which generally leads on the ridges and barrenest parts between river & river, but make directly for a river and take the road along that, which always leads thro’ the richest country, the best cultivated & most populous. thus in going from Paris to Marseilles ascend the Seine to Dijon then fall in upon the Saone at Chalons and descend that and the Rhone to Arles, & then across to Marseilles. so from Paris to Amsterdam ascend the Seine & Marne to Vitry, cross over to Nancy and direct to Strasburg, and thence along the Rhine Etc.

If you should be at Leisure to write from any of your stations, I shall always be happy to recieve a line from you, altho I should not be able to return it unless I could shoot flying. I think it possible you may find some of my friends to whom I inclose letters, dead, as several are old, and I have not heard from them for some time. wishing you all the delights the journey is calculated to afford, and all the benefits of health you wish from it, I tender you the assurances of my great esteem & respect.

Th: Jefferson