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1. Chemical Analysis of Metallic Worlcs of Art found in old 

 graves and ancient fields of hattle.—% On Change of Arra- 

 gonite into Calcareous Spar. — 3. Chemical Examination of 

 the Parmelia esculenta, a substance said to have been rained 

 from the sly in Persia. — 4. Chemical Analysis of Oil of 

 Roses. 



1. Chemical Analysis of Metallic Works of Art found in old graves 

 and ancient fields of battle, by Professor Gobel. 



It is well known that 400 or 500 years ago, the ancients, who 

 were ignorant of the mode of hammering cast-iron, employed, 

 as a substitute for steel, in the manufacture of their swords, 

 lances, spear-heads, &c. an alloy of copper and tin. It is also 

 known, that the Romans and Grecians alloyed copper with tin 

 or zinc, or with one of these metals, and lead, &c. and used 

 them for all kinds of culinary vessels, bronze statues, medals, 

 sarcophagi, vases, and ornaments of various descriptions. It re- 

 sults from my examination, that the ancients did not employ 

 very determinate quantities in the formation of their alloys ; but 

 that they knew well how, in a general way, by the addition of 

 more or less tin or zinc to copper, the alloy becomes more or 

 less difficultly fusible, more or less brittle, or softer, or more mal- 

 leable and brighter or darker in colour. Part of an old sarco- 

 phagus, brought by Professor Ledebour from the Altai, on the 

 borders of China, is cast, and composed of tin and copper, and is 

 as good as the cast arrow-heads of an Egyptian grave. They are 

 distinguished, however, from each other, by the proportions of 

 their constituent parts. The arrow-heads contain less tin than the 

 sarcophagus, but still as much as, by a certain degree of fusibility, 

 to acquire, after cooling, great hardness and solidity ; for the an- 

 cients generally employed one part of tin to from four to six parts 

 of copper. The ornamental articles still met with in old fields of 

 battle, are generally alloys of zinc and copper, with or without 

 tin ; and the ancients appear to have known accurately, that, by 

 the addition of certain weights of tin, the alloy acquired par- 

 ticular colours ; for although the object analyzed contained 

 little tin, yet it is not to be considered an accidental constituent 

 part. 



