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served that they differed greatly from one another, eitherin degree of colour, or in the freedom of their markingupon paper.

This experiment affording little decisive, I repeated theoperation in crucibles, with greater quantities of the ma-terials, that a more exact comparison might be made ofthe colour of the coals, by using them as paints, both ina concentrated and diluted state. Two crucibles werefilled with vine twigs, cut in small bits;" freed from theknots, and thoroughly dried : the mouth of one cruciblebeing then fitted into that of the other, the juncture waswell secured with luting. Small smooth branches of mostof the other kinds of trees above mentioned, were in likemanner inclosed, each in two crucibles, and all of themcontinued about four hours in a strong red heat. Cuttingsof white paper, beaten with water into a paste, such as isCalled papier mac he, that they might take up less room inthe crucibles, and have less air lodged in their interstices,were dried and treated in the same manner; but someflame appearing to burst out through a small crack whichthe vapour had forced in. the lutingj it was necessary totake out these crucibles after they had been about ten mi-nutes in a red heat: the paper, nevertheless, was perfect-ly charred.

The several coals were levigated into fine powder, mixedboth with gum water and oil, and applied as paints, boththin and thick, by themselves, and diluted with diffe-rent proportions of white. All of them, when laid onthick, appeared of a strong full black; it could not bejudged that one was of a finer colour than another. Whenspread thin or diluted, there were indeed some sensibledifferences among them, but neither very considerable,rtor of such a kind as to be easily expreffed or described:they had all somewhat of a bluiih cast, but different per-sons, .

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