I had the honour, a few days ago, of mentioning to you an interesting experiment which Mr. R. Peale had exhibited before a number of citizens; namely, the depuration of foul or putrid water, by simple filtration through sponge, sand, & charcoal;—that he had also succeeded in an attempt to render salt water fresh, and that he was preparing to make the experiment with true sea-water—He has this day made that experiment; and, I am happy to announce, with complete success. I did not indeed see the experiment performed, but afterwards examined both the sea-water, and the fresh-water drawn from it. The sea-water was taken up near Amboy, and was perhaps but little different from that of any other part of the ocean; & the fresh water appeared to me as pure as our best pump or hydrant-water. In the experiment of today, Mr. Peale assures me that the proportion, in bulk, of the fresh water to the ingredient previously added, was as 8 to 1: and he flatters himself that, by farther trials, he will be able greatly to increase this proportion.—

The ingredient he uses (which he as yet keeps a secret) is, he declares, easily procured, or made, in all parts of the world; and that, as an article of commerce, its1 value is greatly increased by the process.

If any thing further should occur, relative to this subject, worthy of your notice, I shall do myself the honour of communicating it.

I am, Sir, with the most perfect respect and esteem—your obedient hum. Servt.—