[45] [Several other analyses of bronzes from various sources have been recently published. Thus Natterer (“Monatshefte für Chemie,” XXI. 256, 1900; also “Chem. Centralblatt,” 1900, I. 1262) examined a corroded bronze statuette from Ephesus. The bronze contained:—Tin 6·09%, lead 4·87%, and copper 89·64%, with traces of zinc.
Bassett (“Proc. Chem. Soc.,” 1903, XIX. 95) gives an analysis of the base of an Egyptian statuette, found in the Nile Delta, probably dating from 200-100 B.C. The base was hollow but filled with lead, and was covered with a thick green coating, which in parts entirely replaced the original metal.
Table I.
| Cu | 50·65% |
| Pb | 6·74% |
| Sn | 2·94% |
| Fe | 0·15% |
| Ni, Mn, etc. | 0·11% |
| Cl | 15·71% |
| SiO2 (as sand) | 1·14% |
| H2O | 11·07% |
| (NH4) | 0·11% |
| 88·62% |
Table II.
| CuCl2 | 29·34% |
| CuO | 46·10% |
| H2O | 11·07% |
| SnO2 | 3·73% |
| PbO | 7·26% |
| Fe2O3 | 0·22% |
| NiO, etc. | 0·14% |
| SiO2 | 1·14% |
| (NH4)Cl | 0·32% |
| 99·32% |
In the second column the chlorine has been calculated as copper chloride, the remaining copper and other metals as oxides.
Traces of calcium were also found, but the amount of sodium was so small that it could only be detected by the flame test. If all the copper had been present as basic chloride (atacamite CuCl2, 3CuO, 3H2O), this would require 26·84% CuCl2, 47·57% CuO, and 10·78% H2O. It would therefore appear that the substance produced by corrosion is less basic than atacamite, and that ammonium chloride may have played a more important part than sodium chloride in the formation of copper chloride, for in this case the sodium was only found in amount too small for estimation.
An analysis of the earliest piece of bronze known, i.e. that from Mêdûm, Egypt (3700 B.C.), gives 8·4% of tin (inner core 9·1%) to 89·8 of copper with a small quantity of arsenic.
An analysis of a celt from the Dowris find (King’s County, Ireland, 1825) gave copper, 85·23; tin 13·11; lead 1·14, with traces of sulphur and carbon. The waste material from the same place yielded 89% copper, 11% tin, with traces only of lead, iron and silver.