From Richard Peters, 10 March 1810
I did not recieve your Letter of the 22d Feby 'till yesterday. I am much obliged by your Attention to my Request relative to the Enquiries on Plaister of Paris. I find that taking an Airing, or indeed a Gallop, now & then on some of my old Hobby Horses, relieves me from the small & sometimes the great Maladies of the Mind. If I can make these Excursions useful to others, a double Purpose will be answered. The Account given by Mr L. Lewis is exactly as I expected. Your Land is not of the Quality calculated for Plaister.