M. Járó - L. Költő szerk.: Archaeometrical research in Hungary (Budapest, 1988)
Analysis - WITTMANN Zsuzsa, BÉLAFI-RÉTI Katalin, DÉCSY Zoltán, ERDŐHALMI-TÖRÖK Klára, KISS—BENDEFY Márta, VASSÁNYI István, VELLEDITS Lajos: Examination of painting materials used by Mihály Munkácsy for his painting "Studio"
The composition of the crystalline inorganic compounds was determined by X-ray diffraction. Quantitative analysis of the metals after micro-digestion of samples of about 0.5 mg or the samples from the infrared spectrometry tablets were carried out by atomic absorption spectrometry. For the nonmetal content of the samples (sulphur, chlorine, phosphorous and nitrogen), modified standard methods were used taking into consideration the quantity of the samples [10-12]. 4.2.2 Instrumental examinations The metal and nonmetal content of the samples can be found in Table 3. In this table, ground I and the whole ground (ground 1 and the so called bitumen ( ground II.) can be seen. It is most likely that sample 10 shows the composition of the original ground. On the basis of X-ray diffraction analysis (CuK^-ray, accelerator voltage 50 kV, heat current 50 mA) and Table 3, the following are found in ground I: calcite(chalk), Pb(C0 3 ) 2 (OH)2 (lead white) and PbC0 3 . The high Zn-content of the sample possibly indicates ZnO, but its most intensive peaks were covered by the peaks of the other compounds. There was no reflection of dolomite on the diffractogram so calcite may have been contaminated by magnesium. The materials contained the contemporary contaminants of production [13]. Perhaps it is interesting that sodium chloride could be shown on the X-ray diffraction spectra. Silicon(Si) and iron(Fe) were found in comparatively large quantities, vanadium and nickel in smaller quantities. Chromium and potassium, as potassium dichromate, could have been a chemical agent in glue which increased solubility in ground I [4]. Cobalt and lead were used as drying accelerators for the drying of oils. The mechanism of the drying process was studied by Grandou [14]. The usage of these metals as accelerators in drying oils mixed with pigments was usual. Cobalt was found in the ground but the presence of lead accelerators could not be proved because of the lead white. The blue colour of sample 6 is linked with its high iron content. The brown colour of samples 2 and 3 is possibly caused by the ground (ground II). We examined only the upper layers of samples 4 and 5. The red colour of sample 4 is linked with its high aluminium content. Sample 5 possibly features ground II by itself. Both of the two samples contain a considerable amount of lead and zinc. The X-ray diffraction spectrum of sample 2 shows the presence of a large quantity of lead white, a smaller amount of calcite and the least sodium chloride. 5. Conclusion Judging from the analytical results obtained from the painting "Studio", it was determined that the canvas was ready made grounded and glued. The main components of the ground are lead white and calcium carbonate, and the organic materials are drying oil and glue. Munkácsy put another dark layer into this white ground, the so called "bituminous" ground, the main component of which proved to be beeswax dissolved in tur-
