THE estimation of constituents in compounds by the blowpipe has been hitherto, as is well known, limited to the process of metallic (or, in the case of cobalt, arsenidal) reduction of oxides, &c., and that with regard to a very few metals only. I now propose to inaugurate a new plan, by which this rapid, elegant, and accurate method of analysis may (apparently) be applied far more generally, and, as I hope, successfully. In my published work “Pyrology, or Fire Chemistry,” I have, with the exception of a few indications (as in the case of the insoluble balls formed by lime in boric acid), confined myself to qualitative research only, but many methods will suggest themselves to the attentive student of that book, by which qualitative may be readily extended to quantitative examination.