326 ]Mr. J. W. Mallet's Rq)ort on the Chemical Examination of Antiquities 



The composition of these specimens agrees in general with that of the articles 

 ■which have been examined by the authors referred to before, and also accords 



pretty closely with the quantities synthetically employed by the ancient metal- 

 lurgists of whose labours we have any account. Thus, Pliny tells us* of the 

 method adopted in his day for making bronze, which, however, he obviously 

 treats of principally as a material for statues and public monuments. " Massa 

 proflatur in primis, mox in proflatum additur tertia portio a3ris collectanei, hoc 

 est, ex usu coempti. Peculiare in eo condimentum atritu domiti, et consuetu- 

 dine nitoris veluti mansuefacti. Miscentur et plumbi argentarii pondo duodena 

 ac selibra?, centenis proflati. Appellatur etiamnum et formalis temperatura 

 reris tenerrimi, quoniam nigri plumbi decima portio additur et argentarii vige- 

 sima : maximeque ita colorem bibit, quem Grascaniciun vocant. Novissima est 

 quae vocatiir ollaria, vase nomen hoc dante, ternis aut quaternis libris plumbi 

 argentarii in centenas aris additis. Cyprio si addatur plumbum, color purpura 

 fit in statuarum pra^textis." The analyses also of antiquities, not of Celtic ori- 

 gin, as those by KLArKOTH,tDiZE,J Mongez,§ Gobel,|| and pupils of Erdmann,** 

 all approach each other within rather narrow limits, and differ little from those 

 at present under consideration. 



The cause of this general accordance is obvious, namely, that the physical 

 properties required in these alloys of copper and tin are only to be found 

 within a small range of variation in chemical composition. Dr. RoBiNSONtt 

 has given it as his opinion, that, when used for weapons, the atomic constitu- 

 tion of Celtic bronze was constantly 14 Cu + Sn ; but though this formula 

 may and probably does represent the best alloy for the manufacture of imple- 

 ments for warlike purposes, or others in whicli similar requirements exist, yet it 

 cannot be said that it invariably accords with the actual composition of the 

 antiquities in question, as No. 6 of the analyses in the Table is near 11 Cu + Sn, 

 while' No. 4 approaches 39 Cu -t- Sn, and Nos. 2 and 7 contain still more copper, 

 though perhaps the former of these should hardly be considered as bronze. 



As on the one hand we must not conclude that a simple and invariable 



* Hist. Nat. lib. xxsiv. c. 9. 



•f Gehlen's Journal, No. 15, and Journal des Mines, Mars, 1808, p. 161. 



X Journ de Phys, 1790. § Mem. de I'Instit. || Schweig. Journ. 60, 407- 



»• Journ. fur pr. Chem. xl. 374. tt ^'^o'^- Koyal Irish Acad., vol. iv. 



