I have found at my return in Philadelphia near a month ago, your kind letter for which i would have immediately returned my most grateful thanks, if it did not contain two articles to which it was my duty to answer, viz. the cements for cisterns, and the papers of Captain Lewis. As to the first, the books containing the prescriptions were not at hand, and i could attain them with some difficulty, but having after unavoidable delays had sight of them, i am able to send you the contents.

1. Cendrèe de Tournay, ciment qui a La proprieté de se consolider dans L’eau et de devenir au bout de quelques annèes plus dur que Les pierres auxquelles il sert de Liaison.

Melez de la chaux pure avec La cendre du charbon de terre, jusques a ce que Le melange pese ¼ de plus qu’un egal volume de chaux pure—Il est necessaire d’ecraser La cendrèe jusques a ce qu’elle fasse une pâte unie et douce, et par La seule force du frottement, et sans y mettre plus d’eau qu’il n’en faut pour L’eteindre

2o Imitation de pouzzolane dont L’efficace est prouvèe—Prenez une moitiè chaux, un quart brique pilée bien pulverisée et passée au tamis, un quart machefer egalement bien pulverisé.

3o Ciment pour Les jointures des citernes particulierement de celles destinèes a garder du vin—Prenez une pierre de chaux, que vous Laisserez et etendre1 a L’air prenez du sang de boeuf, avant qu’il ait caillè, c’est a dire encore chaud; melez ces deux substances, en Les fouettant Longtems ensemble, jusques a ce qu’elles aient La consistance d’une colle epaisse, enduisez en toutes Les jointures.

General observations for the construction of good cisterns—1o to avoid any gravel or stony nucleus of any size whatever in the cement—2o to spread the cement which must cover all the inside (l’enduit) in thin strata successively and equally. It is a work of patience and attention, which is well repaid by the excellence of the cistern.

I am sorry the cisterns of Charleston did not occupy my attention, but i have strong reasons to suspect, they are not well constructed. The water of Charleston is far from being so good as rain water generally is, and differs from it so much in taste and in salubrity, that it is more than probable that in so low a situation and so surrounded by water as Charleston is, the cisterns admit by filtration other waters Now what they take in there, would be Let out if they were situated in a high and dry ground.

Now for Captain Lewis’s papers, i have found it a difficult work, but you may rely on my zeal and assiduity to fulfil your wishes. Several times have i called on Mrs Barton and twice on Mr Pennington her brother, who has great influence on her, and assists her in the arrangement of her affairs, but i am not more advanced than in the beginning. The Dr has Left such an immense heap of papers, and in such disorder; the reclamations for papers and books are so many, that i conceive how the poor Lady is embarrassed how to do. It seems that for a great number of years the Drs Library and cabinet followed the same Law that Dante has inscribed on the gate of hell

Uscite di speranza o voi che entrate.

But i hope there will be an end to this suspence; you will know the result.

The Letters you directed to Knoxville i have also received here, and cannot but blush at the excessive praises, which your goodness bestows on me, but as to the danger of Mr Gilmer catching from me an immoderate taste for ornamental Knowledge, you may well change your opinion, and he will tell it himself—Curious and strange as it may seem, he has received from me during all the voyage more hints and dissertations about what i conceive to be the real interests of his country and the means of her reaching the high destinies to which it seems destined by nature, than even about the plants we were meeting. He must have wished to find many of his countrymen so zealous on that subject as his european companion; as i Love the country and Like his mind and his heart, my grand point was to help him with whatever was in my power to do that good which i myself would have attempted, and fit him to se mergire civilibus undis with glory to himself and his country.

I come Lastly to the Kindness you show to me, in the interest you take in the future steps of my Life. As Long as i Live will i feel your goodness, and keep a grateful sense of so much kindness. Your judgement of European present and future affairs, is what myself think; but i see Little chance of escaping the necessity of returning there. What i can do is not rashly to chuse Paris for my residence, till i see the turn things take. As Long as i shall remain on this continent i will perform with devotion and gratitude my annual pilgrimage to Monticello, and when in Europe i will turn very often my eyes to the West and think of the real greatness and dignity of the man who has Laid such a claim to my respect and heartfelt gratitude.