To the silicate samples like glasses or rocks were added sodium carbonate and the diluent consisting of germanium dioxide and twice the amount of graphite powder, in the ratios 1:1:2 or 1:1:40. The thoroughly mixed sample was put into a carbon electrode and excited by the d.c arc of 200 volts and 8 amperes. The spectra recorded photographically were processed by the usual methods. The line of germanium at 3067.0 or 2829.0 A was used as the internal standard, the latter being used for samples containing larger amounts of iron. The elements Ag,Al,Bi,Ca,Co,Cu,Fe,Mg,Mn,Ni,Pb,Sb,Sn and Ti can be determined with the relative deviation of about 10% and Si of about 5%. The concentration ranges applicable are Ag 0.001~Ti0.6% and those of major components, Si02 and PbO are ca.15-100% and 10-75%, respectively. The purpose of the present investigation is the application of specrographic methods to the study of ancient glasses.
