PAINTINGS, RESTORATION AND PRESERVA TION OF. It would be extremely difficult, if not impossible, to determine at what date the restoration of painting was first under taken.
Ancient restoration does not reveal any technical processes of much interest ; no real progress was made in the art of picture restoring until the i9th century. It is true that such men as Le Primatice, J. B. van Loo and even Chardin, were sometimes entrusted with restorations; but it was the exception for them to undertake such work. As a general rule the touching up of dam aged pictures was, and unfortunately only too often still is, entrusted to inferior artists who regard the restoration of paint ings as an unimportant work.
The result of this has been that during past centuries, no tra dition has grown up, and in consequence of the low esteem in which that branch of art has been held, no outstanding personality has devoted his authority and skill to putting an end to this regrettable state of affairs. It must be added that at those periods when the art of painting stood high in popular favour, the most skilful forgers have been found among the restorers of pictures. Such men often had considerable skill in their own way, even though they were without real talent ; and a study of the history of painting frequently shows that unscrupulous restorers have made use of their knowledge in order to make alterations or addi tions to pictures for purposes which certainly had nothing to do with art.
We may leave on one side the undesirable activities of bad work men, and turn to the development of the art of restoring pictures which has now been brought about by experts.
clear water. (3) Add to the permanganate solution hyposulphite of soda -). Leave the picture in this solution for ten minutes and add ten drops of hydrochloric acid. (4) When the paper has become white, wash it in water for half an hour and dry the whole between sheets of blotting paper.
The diseaSes from which paintings may suffer are of various kinds. Their treatment may not be so urgent as that of human ailments, but it is just as difficult and delicate in its own way. It necessarily varies with the different schools, pictures and artists, since the problem of restoration is closely bound up with the whole technique of the picture to be restored.
A picture, no matter at what date it may have been painted, consists from the material point of view of two elements: (I) the supporting structure, which may be wood, canvas, paper, card board, a wall, etc.; (2) the paint which is superimposed on the supporting structure, and which constitutes the picture itself.
In addition to these two principal elements there are two other factors which appear to be of a secondary character, but which are nevertheless of great importance. The supporting structure is almost always covered with a layer of fish-glue on which is applied some isolating substance such as plaster, carbonate of lime or white lead. Modern painters, it is true, sometimes paint their pictures directly on the canvas, or on a wood panel; but in the course of centuries it has always been found better and more con venient to cover the supporting structure with some isolating substance before beginning to paint. This substance is an element of such importance from the point of view of the restorer that it must be considered separately.
Finally, the fourth element which constitutes the picture is the final varnish, which is in some cases replaced by a thin coating of encaustic.