It would seem that this coin contains a trace of gold, as its specific gravity is higher than that of pure silver, which is 10.48. From the specific gravity of this remarkable coin it would appear that it consists almost entirely of silver, but from its yellow tint as compared with a pure silver coin, such as a tetradrachm of Athens, it is certain that it must contain a larger proportion of gold than is here indicated, but the yellow colour is produced doubtless chiefly by the addition of copper. Such an alloy being lighter than silver, would affect a calculation based upon the assumption that the coin consists of gold and silver only. As the specific gravities of numerous staters and hectae of Cyzicus have already been calculated by Dr. Hofmann in the article above referred to, by Dr. Hultsch, Zeit. f. Num. xi. 165, and still more recently by Prof. P. Gardner, in the pages of the Numismatic Chronicle (supra, p. 188). I have not added any of these to my list. I am indebted to Mr. W. M. Flinders Petrie for suggesting to me the following table, which shows the theoretic curve of mixtures of gold and silver by calculation. By means of this table, the specific gravity having first been ascertained, it is easy to read off the percentage of gold contained in the mixture, presuming that the examples selected are fused, and that they contain gold and silver only. |