Having just finished some experiments of a pretty extraordinary nature, I make haste to give you some account of them.

By means of Mr. Parker’s lens, I heat an earthen retort, filled with moistened clay. When the neck of it is well luted to the upper orifice of a glass receiver, which is placed in a basin of water, and a glass tube communicating with the inside of the retort. In consequence of this, the water from the clay comes into the receiver, while the air in the receiver passes thro the retort, and is delivered out a; the water in the basin rising within the receiver, and covering the retort. If it be inflammable air it comes thro inflammable, if nitrous nitrous. This must be by the air losing its aerial form while it combines with the earth of the retort, and recovers its aerial form in the inside of it. If the retort was not perfectly air tight, the water could not rise within the receiver. Spirit of wine comes thro the retort into the receiver, just as the water does.

This renders one of my proofs of the conversion of the water into air fallacious, after I had fully satisfied even Mr. Kirwan of of the reality of that conversion. Another experiment is not so easily explained.

Making water to boil in a glass retort, I make the steam go thro a red hot tobacco pipe; When I always get much air mixed with the steam. In the same manner spirit of wine makes inflammable air, and spirit of nitre the purest dep[h]logisticated air. But if the tobacco pipe be not hot, I get only vapour, and no air from any of the liquors.

I cannot in a letter enlarge on all the particulars of these experiments which excite a good deal of attention here. I shall lay them before the Royal Society, and pursue them at my leisure as soon as I get home.

I thank you for your excellent Address to your neighbours, and am most disappointed in not meeting with you here. With the greatest gratitude and respect I am Dear Sir Yours sincerely