My being at the Pot ash works of Richd. Johns (on business) when Mr. Jefferson came there, to make some Enquiery respecting the manufactury of Pot and pearl-ash, (and, Expressing an intention of beginning the business in the forests of Virginia, where he purposed having the timber Cut down and burnt in the open air,) I considered it my duty to speak a few words on the occasion, having once been Engaged in that undertaking. I informed you sir, that it did not answer the Expected End. I had an Amazing quantity of wood prepared and piled up in large heaps and set fire to, and Expected to have a plentiful harvest of ashes to hale to the works, and was much disappointed. The rapidity of the fire was so excessive as to raise the ashes as they formed, and the wind wafted them away. I am told the Russians burn their wood in Kilns, built under the Knolls of hills, into which the wood is Easily rolled, and, where ‘tis consumed to advantage, but the construction of these kilns, I am unacquainted with, therefore must leave it to be Explained by some person who may have seen it. Probably I may be able to find out such a person, and should you Express a wish of that sort, I will then do it chearfully. With respect to making good Pot and Pearl-ash, be assured it is but a simple thing, in which care is the Essential matter. The Lye must be Clear, or it will not be good after all the trouble, and the Lye ought to be strong, ere it is Evaporated into black salts, in order that less time may be required, and, consequently, less wood, and less Expence. The process of making these salts into Pot ash, is very simple, many artists1 melt them Easily in open kettles, I have been inform’d, but my kittle was always covered with sheet Iron, and I think Richard Johns has improved on it. His fire is so intensely hot as to burn out all the black vegetable oil, which, when left in, is the Cause of the sulphurious smell found in some ill manufactured pot-ash, which is unfit for the bleaching of Linnen. Should Mr. Jefferson incline to make Pearl-ash, it will be necessary to have an ovan for scorching the black salts, as the artist terms it, that is, to burn out the blackness of the salts, with a moderate fire made with dry oak, which is the best of wood for the purpose, and after the scorching is completed, it is then to be put into the kettle with a quantity of water sufficient to imbibe the alkalis2 and set to boil, after which put all the disolved part into a Clean tub to settle for some days, when the white Lyes are to be returned into the kettle, to be Evaporated into white Pearl ash, and carefully stirred, till Evry Lump on breaking, is found to be thoroughly white, and this is the whole art of making Pearl ash in Kettles. This new mode of boiling the scorched salts and putting the solution into the tub to settle, is productive of another good End, i.e. that of leaving all the Neutral-salts, adhering to the side and bottom of the tub, therefore this is pure Pearl-ash, and is of more value (if duely Estimated,) than what has not gone throug this process. Should Mr. Jefferson require further information, I would advise him to apply to Mr. Johns, who is competent to it,3 and makes as good Pot and Pearl-ash, as any I have ever seen. I am sir, your sincere well wisher & huml. servt.