The earliest copper alloy of the British Bronze Age is arsenical copper, a material relatively short-lived when compared with the succeeding tin bronze but of no little importance when tracing the stages and progress of prehistoric metal working. Like tin, arsenic functions as a mild deoxidant and confers the useful property of work-hardening upon the metal. Copper-arsenic alloys need to be strengthened by cold working, and it was probably this requirement as much as any other that would have led to their eventual disuse and replacement by cast tin bronzes. The normal source of arsenic for such alloys is generally agreed as a constituent of the copper ore actually smelted, usually the grey tetrahedrite tennantite mineral (Coghlan and Case, 1957; Tylecote, 1962), although other suggestions have been made (Charles, 1967).
This is an article about pottery analysis and the nature of A1 ' Ubaid contact with Saudi Arabia. The discovery of 'Ubaid sites in Saudi Arabia has been of the greatest interest to Middle Eastern archaeologists; neutron activation and petrographic analyses of the pottery from these sites, published here, have yielded unexpected results, with profound implications for the or@ins of civilization in Sumer.
The heat capacity of hexagonal phosphorus pentoxide has been measured from 12 to 324°K in an adiabatic calorimeter. The entropy of the crystals at 298~15°K was found to be 54.68k0.1 cal deg.-l mole-1. Thermodynamic properties from 5 to 330°K have been calculated from the experimental results. * seconded to N.C.L. from Albright and Wilson (Mfg.
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