| Description | (Directed to the Hotel de Chaulnes, rue d'Enfer.)
My dear Son,
Your letter of the 30th ultimo gave me infinite pleasure: the stile is elegant, the grammer just, and the orthographi correct. I beg you will continue to write to me often, for there are no other favours you can bestow upon me that will be half so acceptable. I am also pleased to find that you are resolv'd to change your language, and I hope you will continue in that resolution untill you return to England.
As you are now come to that part of Mr. Sage's course of chymistry which treats on minerologie I beg you will give me some account of his general theories, particularly his notions respecting the composition of simple metals. The old doctrine in this country is that all metals are composed of a metalick earth (sui generis) and phlogiston: which phlogiston, when seperated from the earth, is inflamable air, or some thing like it, because inflamable air is not only seperated from the metal, leaving the remainder in the form of a calx, but that same inflamable air may be again reunited with that same calx and thereby form the same metal as before, or that same inflamable air or phlogiston may be united with the calx or metalick earth of another metal and thereby form such other metal in a ductile and malable state.
But the new doctrine amongst the French chymists is that metals are according to their respective kinds, consist of one homogenious substance, and that by combineing air with that metal it forms a calx, and again by driving out that air by heat and at the same time applying some inflamable substance with which the air hath a greater affinity than with the metalic earth you get rid of the air and the remainder is a maleable metal.
This is only a slight out line of the two different theories, either of which serves to reason upon, but which is the veritable theory I will not pretend to. Hear all sides with candor, see all the experiments, read all the modern authors, and then judge for you[r] self.
The manner in which Dr. Priestly [Priestley] combined inf[l]amable air with the calx of lead or tin or iron was as follows: He took a glass bell full of inflamable air, which he placed in a shallow [At this point is inserted a small diagram] vessell with water W; in that stood an inverted crucible C, upon the top of which was placed the calx at F, upon which was a pencil of the sun's rays, collected by a large lens (call'd a burning glass) L, the focus of which falls upon the calx at F, which calx absorbs the inflamable air, and of consequence the water rises in the glass and thereby shews howmuch of the inflamable air hath been eat up by the calx.
There is much to be said on both sides, and therefore I leave you to form your own opineons.
I will send you Kerwin's little book upon this subject the first opportunity, and I will also send the cotton stockings, but it is ten to one but they are too little or too big. It would be well if you could discribe or send a size.
I was sent for to town by Mr. Pitt and the Privy Council about a new copper coinage, which I have agreed for, but at a very low price; yet nevertheless it shall be the best copper coin that ever was made. I am building a mint and new manufacture for it in my farm yard behind the menagery at Soho, where I shall be closed engaged for 1½ year without going to Cornwall. Pray go to Mr. Droz and see and tell me exactly what state he is in with my sous.
I have not yet wrote to Metman, I am so very busy.
My compliments to Mr. Manuel and all my good friends dans le rûe Coqheron. Adieu, my dear Matt. I am ever your humble servant,
M. Boulton
[Edited transcript.] |