A long, and interesting Session of Congress—which did not close until the first day of this month—and the Laws which required to be carried into execution promptly; will, I am persuaded, be admitted as a reasonable excuse for my not writing to you since the 20th of Feby last, agreeably to assurances then given. But what apology can I offer now, that I am about to give you the result of the enquiries you requested me to make, when it will be found to fall so far short of what you might have expected, from the time which has been taken, to render it?

Your wishes on this head, I communicated to Richard Peters Esqr.; who is one of the most intelligent, and best practical, as well as theoretical farmers we have; with a desire that he would advise with others, and condense their observations in a summary Statement.1 Why this was not done—and why he could do no more—you will find in his own, original letter, with the questions and answers therein enclosed.2

To Mr Peters’s experience with respect to Gypsum as a manure, let me add the following, as an unequivocal evidence, that it has no effect on stiff—heavy land—that does not absorb, or permit the water on the surface, occasioned by super abundant falls of Rain or Snow, to penetrate quickly; which is the case, generally, with the Soil of my Estate, at Mount Vernon. The experiments, & proof to which I allude, were made eight or nine years ago; at the rate of from one to twenty bushels of the Plaster of Paris to the acre (among other things, to ascertain the just quantum to be used)—I spread it on grass grounds, and on ploughed land. On the latter, part of it was ploughed in; part harrowed in; part scratched in with a light bush; while another part lay undisturbed, on the surface. All with Oats, in the Spring. But it had no more effect, in any instance—then, or since, than so much of the earth it was spread over would have had, if it had been taken up & spread again.3

If any thing should hereafter occur on this, or any other subject, which I may think worthy your attention, in this interesting branch of your pursuits, I shall not fail to communicate them to you;4 being with very geat esteem, respect & consideration Sir, Your most Obedt, and very Hble Servt