Faraday to William Richard Hamilton   8 June 1837

R. Institution | 8 June 1837

My dear Sir,

The particles¹ you sent me seem to have come from a prepared surface. Being put into a dilute acid a portion of adhering matter is dissolved and the principal portion left in an untouched and cleaner state. Being then washed and dried it is found that this consists of carbonate of line and a combustible substance which protects the carbonate from the acid. This combustible substance when heated is destroyed, leaving charcoal and then acid can attack the calcareous matter. The combustible substance may perhaps contain wax, but it does not present undeniable traces of that body. It is in small quantity as compared with the wax present in Mr. Donaldson's specimens². There is no mineral color present in the particles, except it may be a small portion of iron color, and that I rather judge to be accidental. Whether or no any animal or vegetable color had been used is more than I can say.

I am dear Sir, | very truly yours | (signed) M. Faraday

W.R. Hamilton Esq | &c &c