£64 Contrilmtion towards the assaij'nig of Coins. 



ing to the different uses to which it is applied : for jtatueS, 

 bells, and cannon, it is called bronzcj bell metal, and gua 

 metal. 



But a? copper by its mixture with tin becomes denser 

 and harder, acauires agre.ucr sj ecific gravity, and becomes 

 luore sonorous, it is in the sa no proportion nndered more 

 tender and brittle. It consequently ceases to be malleable. 

 Pliny says * Caldarhtm J'und'ilur tantum, malleis fragile. 

 The Greek coins, therefore, consisting of such nnxed 

 metals, do not seem to have been struck, but to have been 

 cast, and the circumstance of their beino; o;enerallv concave 

 on one side must be considered as a consequence of the 

 contraction or warping occasioned by their coolinjr. 



Among the mixtures [tempered lira) of copper meiitioned 

 by Pliny, there is one in particular, which he calls ces te- 

 verrif/niin, which is found in the Syracusan coins : it con- 

 sists of 100 parts of copper, 10 parts of lead {plumbum 

 vigrimi), and 5 parts of tin [plumbum argcn(nrinm) ', of 

 which mixture he says that it appears with that colour 

 which he calls the Grecian [color Grcccaniciis). Under the 

 term plumlum nigrum of the Roman writers we must 

 understand our lead. Tht'ir plumbum argciitarium, album 

 candidum, however, is not lead, but the^Kao-o-fT-siOf of the 

 Greeks, or our tin ; and Plinv clearly means by it tin fused 

 from washed ore. The word sfanuum however occurs in 

 Pliny, but this word was not used by the Ronians to denote 

 our tin but a mixture of silver and lead, or that substance 

 which, in the languaoe of the German miners, is called 

 werld'lei/f, or merely the uerk. In regard to the Roman 

 copper coins, they consisted, as already seen, either of pure 

 copper or of a mixture of copper and zinc, which 'a as called 

 by the Ronians aurkhalciim, or orictialcum ^ and also ces 

 Corinthiannu, and seems to belong to the same class as our 

 brass, pinchbeck, similor, &c. JNJctalHc zinc however was 

 at that time entirely unknown, and no traces of it are to be 

 found before the 13th century, at which time it was men-' 

 tioncd by Alberlus Maiinus. 



It clearly appears, from several passages iri antlcnt au- 

 thors, that the antients emploved a melhod for preparing 

 this mixture of calamine [cad'mia fossiUs) similar to that 

 which we employ for the preparation of brass. Festus says 

 expressly, cadiuia terra ocs coiijinfiir, vt fat nr'ichalcum. 



jBut it is pro.ed, by a passage in Aristotle, that another 



'' Lib. xxxiv. cap. io. 



+ Ltal FrdiTi \vhitl\ tlie silver co.. twined with it in the rre has not 

 been SLiMiatcd. Euir. 



peopk, 



