Achaeometrical Research in Hungary II., 1988

BIBLIOGRAPHY - SUMMARIES - ANALYSES

complicated tube connections, elbow pipes and hardware of all sorts. Leaded bronze was used to improve the alloy's casting properties. In addition, the Aquincum organ builders used This alloy to decrease the friction of sliding parts, as the sliders and slider chest components. Copper was used for the wire hooks which flexibly connected the sliders with the actuating means of the organ. Pure tin served as a solder component and as a protective coating or lining material. The inhomogenity of the ancient metals created problems when sampling for analysis. Chemical analysis methods are usually connected with destructive sampling. In our case were applied microsampling methods which provide milligram quantities for the Investigation by micro-spectrochemical analysis methods. Gegus E.: Micro-spectrochemical Analysis Methods of Ancient Copper Alloys and the Organ of Aquincum (University of Veszprém). Abstract = International Symposium on the Organ of Classical Antiquity. Sept. 1-4, 1994 Budapest, Hungary, (1994) Paper in press. Investigation of precious finds requires non-destructive or quasi-non-destructive analytical methods of high detection power. For This reason micro-spectrochemical methods were chosen for the purposes of analysing selected parts of the Aquincum organ on the occasion of its restoration in 1970. Since local analysis by using XRF or other direct spectrometrical methods were not applicable in This case, several mg-quantity samples have been taken from various parts of the instrument. Qualitative information on the chemical composition was gained by using the laser-micro-spectral analysis method. The microchemical variant of our tube-electrode spray method was applied as a "quasiabsolute" analysis method for These samples. A quantity of 10-15 mg-s was dissolved in aqua regia, and a solution of 2-3 ml was introduced into the high voltage spark acting between graphite electrodes. The excited atoms of the sample material emitted their characteristic radiation, which was resolved to a spectrum in a plain-grating spectrograph. Calibration of the analytical method was carried out using reference solutions composed of standard solutions of elements in calculated ranges of concentration. Major and main element contents of samples were determined quantitatively. A total evaporation process in ac arc was adopted for the detection of minor and trace elements in samples having sufficient quantity of 20-30 mg-s. Total evaporation was carried out in a 7 amp. ac arc during 80-90 s from the cavity of a graphite electrode. Spectra resolved by using a quartz spectrograph were recorded and evaluated. Calibration of the analysis method was solved using standard sample series' of pure copper. Results of the analyses are composed in a table. Ancient copper alloys were always significantly inhomogeneous. To study the measure of This heterogeneity, systematic investigations were performed by a laser-micro-spectral analysis method on ancient bronze coin samples. Gegus E.: Investigating Coins by a Laser-micro-spectral Analysis Method (University of Veszprém). Abstract = The Application of Scientific Methods for Investigating Coins and Coinage. British Museum/Royal Numismatic Society Symposium, Sept. 22-24, 1994, London (1994). Paper in press. Elemental composition of coins is characteristic of their origin and type. As a practically non-destructive method, laser-micro-spectral analysis is especially suitable for 299