ANTIQUITIES. 



663 



it is porous and brittle; and, when 

 forged, too soft. The ancient 

 weapons and utensils being of a 

 hardness which this metal does 

 not possess, it was long supposed 

 that the ancients had some me- 

 thod of hardening copper, as we 

 do iron and steel. But chemical 

 analysis has shewn the falsity of 

 this opinion, and demonstrated, 

 that these weapons and instru- 

 ments were not pure copper, but 

 an alloy of this metal with tin, 

 which we call bronze, and which 

 was the tss, brass, of the Romans. 



The weapons, instruments, and 

 statues, which have been dug out 

 of the ground, evidently prove, 

 that the property of tin to impart 

 hardness and density to the metal 

 alloyed with it, was known and 

 employed by the most ancient na- 

 tions. All these objects occur of 

 bronze, but none of pare copper. 

 It is astonishing, that this prac- 

 tice of imparting to copper, by 

 alloying it with a certain portion 

 of tin, a hardness sufficient for 

 sword-blades and other cutting 

 instruments, should have been so 

 generally followed by the ancients, 

 notwithstanding the want of tin- 

 mines. All the tin they used 

 they were obliged to procure from 

 the Cassiterides, the present 

 Cornwall, and the trade was ex- 

 clusively in the hands of the 

 Phenicians. 



Having had an opportunity of 

 assaying several fragments of me- 

 tallic antiquities, I conceive it 

 may be of some utility to make 

 public the results, as a supplement 

 to the few accurate analyses hi- 

 therto made. 



The fragments to be analysed, 

 being first weighed, were put into 

 a phial, into which were poured 



six or eight parts of nitric acid of 

 the specific gravity of 1-22, and 

 digested in a sand-heat till com- 

 pletely dissolved. The contents 

 of the phial were then diluted 

 with a sufficient quantity of water, 

 and the mixture left to stand till 

 all the oxide of tin had fallen 

 down, and the azure liquid ap- 

 peared quite clear. Tl)is being 

 poured off, the oxide of tin was 

 collected, washed repeatedly with 

 water, dried, heated red-hot, and 

 weighed. It was found that 100 

 parts of calcined oxide of tin 

 equalled 80 parts of tin in the 

 metallic state. The nitric solu- 

 tion was tested in the usual way 

 for silver, iron, lead, and zinc. 

 When it was found free from 

 these metals, as in all the follow- 

 ing inquiries it proved, it was 

 easy to calculate, by deducting 

 the quantity of tin found, the 

 proportion of copper, which was 

 likewise obtained by the common 

 methods. 



1. Analysis of an antique stvord. 

 In a collection of antiquities at 

 Berlin, found on digging into 

 some ancient graves in the march 

 of Brandenburg, among several 

 articles of Bronze, as spear-heads 

 knives, ornaments &c. are two 

 swords : but the place where they 

 were found is not known. One 

 of these swords was broken, the 

 other entire. Their composition is 

 the same : they are both covered 

 with the green shining rust called 

 patina. The sword in question 

 weighs seventeen ounces, and 

 is twenty inches long : the blade 

 sixteen and a half, and the hilt 

 which is rivetted, three and a half. 

 The blade is two-edged, and one 

 inch and a quarter broad for two 



