166 



is impossible to ascertain its component parts without the destruc- 

 tion of the medal or some portion of it, its ingredients can only be 

 conjectured from its sensible quaHties. It is much paler than com- 

 mon brass ; does not readily tarnish by exposure to air ; it might 

 be mistaken for pure gold, did not its specific gravity immediately 

 detect it, as it feels nmch lighter than a conmion brass medal of 

 similar magnitude. Its weight in air is 262,76 grains, and its loss 

 in water 31,16 grains, giving a specific gravity of 8,45. It has 

 another remarkable property, which distinguishes it from modern 

 metals : it is very sonorous, and thus it seems identified with the 

 j^aXitof '-A-xu^ of the New Testament ; which may have been the ob- 

 ject of the Apostle's allusion in his epistle to the Corinthians, as well 

 because it was liglit, as because it was " sounding."* These qua- 

 lities perhaps arise from a combination of copper, zinc, and tin, 

 alloyed with a small portion of gold and silver ; the levity and 

 paleness depending ui)oii the first, the sonorous properties on the 

 second, and the resistance to oxydation or tarnish upon the last 

 ingredients. The Ancients are known to have used all these me- 

 tals ill combination with copper in their coins and medals. -j- The 



• Lightness of character, "indicated bj' an allusion to lightness of weight, is a common 

 mode of illastration in the sacred writings. The Psalmist says of men of high and low degree — 

 " To be laid in a balance, they are lighter than vanity.''— Ps. LXII. v. 9. Vessels of " brass 

 without weight" are mentioned in Jeremiah; but it probjbly alludes to their quantity, and 

 not their quality. 



•]- It is a remarkable property in the combination of zinc and copper, that the yellowness of 



the compound increases by the addition of zinc, till it becomes equal to the quantity of copper. 



From that point it grows p.iler, till it b-.-conios white. This circumstance would indicate a 



large proportion of zinc in the compositian of the medal. 



Newman's Chem. p. G5. 



Zinc and copper for.nod the substance called Ca.iiwia, aiwl tiii has been detected in the 

 analysis of ancient coins. Tin gives its sonorous properties to aiodern bell metals. 



Dyzes An. .Journal Physique 1790. 



