X-RAYS AND ART

Otago Daily Times, Issue 18444, 4 January 1922, Page 6

X-RAYS AND ART

The story is told of an American who once purchased .in' excellent Titian in Italy, and in order to get it out of the country—the export of old works of art being,, of course, forbidden in Italy—, caused a landscape in the'modern 'taste to be painted on _ top. His ruse ‘ succeeded, and on his arrival in London he took bis picture te a dealer to have the landscape cleaned off. Not hearing anything from the dealer for/ a fortnight, he rained in person to, inquire how the cleaning process was progressing. l "Pretty well, said the dealer, “we have got off the landscape, and we have got off.the Titian, and we have come down 'to ,a portrait of George IV in his coronation robes, and we the lot.” Now it seems a pretty far cry from old pasters to X-rays; but, nevertheless, if that American had been really, smart, he would have had his'picture examined by a radiologist before' making his purchase, and thereby would have saved his conscience, his time, and--his money, because the X-ray examination would iq all probality have revealed George IV immediately. This hew method of detecting "fakes" in old masters was first introduced by Faber in Germany about 1914, ’ But the method has recently been developed with startling results by Dr Cheron in Prance. As is well known, X-rays pass more easily through some - substances than others; and, broadly 'speaking, it is possible to obtain quite a good X-ray photograph of an old painting, while a modem painting gives a flat photograph without any detail whatever., The three materials which go to the making of an oil-painting are me canvas or other material upon which the picture is painted, the priming or sizing of the canvas,- and the colours or pigments used. Before the Introduction of the X-ray, method, the detection of. fakes depended largely on the examination of the canvas, etc., under the ; taicroscope. The X-ray method, however, goes further. The sizing used in old pictures was usually a mixture qf carbonate of lime and glue, while in modern , work the sizing consists of whitelead. A measurement of the absorption of the rays indicates the presence or absence of metal in the sizing. The chief advantage of the X-ray method, however, consists in determining whether the pigments, used are old or modern. The pld painters used, mineral pigments practically entirely while modern colours are either vegetable qp belong to the aniline group, the use of which dates back only 50 years or so. The sole exception is white, which is always* a mineral pigment, and therefore absorbs the X-rays. Dr Cheron has prepared a table, of absorption of the pigments employed by the old masters. Beginning with those which* absorb the rays, and therefore appear light in the X-ray, photographic negative, and . ending' with those which are transparent to the rays, the pigments stand in the following order;—Carmine, cobalt 1 blue, burnt sienna. English vermilion, orange, chrome yellow. A picture recently examined was a painting of a party of merrymakers danc- ‘ ing outside an inn, attributed to the Flemish painter Van Ostade. The examination gave startling results. The merrymakers vanished entirely, showing thereby that they were of modern origin, and a farmyard scene appeared, in which could be traced two peacocks and various duoks and fowls. Another picture examined by Dr Cheron was a painting in the Louvre known as . the “Koyal Infant at Prayer.” It was believed from certain documents that the original background had deteriorated, .and had been superseded by a black background. The X-ray examination proved this to have been the case. The black background, being a non-metallic pigment, was transparent to the X-rays, and a background of lighter tone was shown to. be underneath. When tiie picture known as the “Madonna of the Star” (seventh century) was examined, the' X-ray photograph showed a wide white band crossing the centre' of the picture, indicating that the picture had been restored very skilfully ' in recent times. . It was a/ common practice in the past for the owner of a painting to associate himself permanently with Tus property by having himself painted in an approx priate attitude and dress Over an-original figure in the picture; Several cases of this fiature have beau revealed by X-rav examination—the original figures becoming plainly visible in the photograph; The development of the method will make the faking of valuable old masters well-nigh impossible. But .it will also provide a new terror for curators of national collections, by showing up alleged , masterpieces for the purchase of which i they may have been responsible.—Chambers’s Journal. • .4