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genious artist, i$ often in business produced with this ma-terial.

As different forts of pitcoal, and different pieces fromone pit, differ much fr6m one another in degree andspecies of colour, some care should be taken in the choiceof them, according to the purpose they are intended for.All the sorts, at least all which I have tried, require longgrinding in order to their being reduced into a powder ofsufficient fineness.

III. Black sands.

The black sands, one of the brightest and most beautifulof which is found in Virginia, lose their colour on beingground into powder, and hence cannot be used as pig-ments. There are however cafes, in which they may cort- 1tribute to the embellishment of certain works, by beingstrewed upon oil paintings for a sparkling black, in thesame manner as smalt is strewed for blue. In this intenttion they are used on writings, preferably to the white sands,as they do not weaken the colour of the ink, but coincidewith its blackness, and give an agreeable lustre.

IV. Black-lead.

Ttns mineral is dug in our own country j and is here,as Dr. Woodward observes, in the preface to his methodof fossils, more plentiful, and of a better kind, than inany other part of the world. According to Dr. Plott’saccount, in the Philosophical Transactions, No. 240, it isfound only at Keswych, in Cumberland, and is there calledwads of kellow, by which last name, as we have alreadytaken fiotice, an earth like the black chalk is distinguishedin other places.

The colour of black-lead, rather a deep shining bluishgrey than a black, may be seen, diluted a little, in the black

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