Page:The museum, (Jackson, Marget Talbot, 1917).djvu/171

Rh one, for the varnish acts as a mastic to hold the pieces together and at the same time by keeping the air out prevents further decomposition.

.—Of all objects in our museums the most difficult to care for are bronzes. These, especially such as have been for a long time buried in the earth, are subject to disease. One form of this is highly contagious and likely to be fatal to the object it attacks, and the others, while not communicable, are yet dangerous unless cared for. Should any bronze in a collection show signs of the first of these diseases, it must be isolated at once or all the other objects in the same case are liable to become infected. So far, no cure has been discovered for this disease although its progress may be arrested by placing the object in an air-tight case with pans of calcium chloride in the bottom to absorb any excess moisture in the air of the case. The first sign of the disease comes in pale green spots which gradually grow and spread until the whole surface of the object is covered and a fine green dust falls about it. A paraffin coat holds back the damage and if the case is not bad an electrolytic operation may cure it. The French process is the most satisfactory and simple of any, and will be found fully described in the introduction to the catalogue of Bronzes in the Metropolitan Museum by Gisela