[ 2H ]

pcriments made to determine this point it appeared, thatthere is some foundation on both fides; and that, bothwith the smallest and the largest os these quantities ofzinc, the metal proves more like gold than with theintermediate proportions.

One part of zinc and three of copper formed a com-pound of a brassy yellow colour, but rather brighter thancommon brass, and at the fame time more brittle : whenbroken, its texture appeared partly fibrous, and partlygrained.

On increasing the quantity of copper to four, five, fix,eight, and ten times the weight of the zinc, the metalproved more and more tough, of a fine grain without anyappearance of fibres, and its yellowness more and moremixed with a reddish cast, like that of gold alloyed withcopper. The best coloured mixture, obtained by anaugmentation of the copper, consisted of five parts ofcopper to one of zinc : even this, however, differedgreatly in colour from fine gold. A mixture of ten partsof copper and one of zinc looked like gold somewhatworse than standard, and hammered extremely well.

On diminishing the proportion of copper, from thrice,to double, equal, and two thirds of that of the zinc, thecolour was improved much more than by an augmentationof it, the compounds proved much more brittle, andwholly of a fibrous texture, without any appearance ofgrains: they broke over short on trying to bend them;and fell in pieces under the hammer. Equal parts ofcopper and zinc, or a little more zinc than copper, seemedto produce the finest colour: these mixtures, in the mass,had a near resemblance to pure gold; though strokesdrawn with them on a touchstone were remarkably paler,looking almost white when compared with those of thegold. And indeed all the compositions I have examined;

whether