Analysis made on April 22, 1931, a panel with a painting »The Entombment«, the other side with three saints – St. Giles, St. Gregory and St. Jerome (Chemical Laboratory of the National Gallery in Prague)

Two samples, the red vesture of St. Giles and the red vesture of St. Jerome, were analysed in the laboratory. The binding media of the samples and the nature of ttx red organic lake were determined. For testing the adhesive s microchemical tests for the presence of oils, proteins and polysacharide s (vegetable gums) were applied. The microchemical tests were supplemented by histochemical staining of transversal sections. Sudan Black B and Amido Black 10 B in three varieties were used as tests for oils and proteins, respectively. Red organic lake was analysed using thin-layer chromatography. Microglasses covered with Cellulose MN 300 Ac 0.3 mm thick and a developing system ethyl acetate, tetrahydrofurane and water were employed. Detection of dyes was made with UV light of 254 and 366 nm wavelengths. The medium in the sample of the red vesture of St. Giles is water soluble, based on polysaccharides. The medium of St. Jerome´s red vesture is an egg tempera, probably whole egg. Identification of red organic lake by thin-layer chromatography proved it to be madder lake. The red colour of the vesture is also constituted by cinnabar, coal black and white lead. A detailed report is deposited in the Archives of Historical Art Technology, code number I 006.


   author
Jindřich Tomek, Dorothea Pechová, AHVT I 006 (M. S.)

Master of the Třeboň Altarpiece, The Entombment, about
1380 (courtesy National Gallery)