CONSERVATION OF ANTIQUITIES — WERNER 597 



When mixed with a hardener, this sets in about 10 minutes at room 

 temperature to form a glass-clear solid that adheres well to bronze. 

 The degree of shrinkage is also very slight so that this resin is an 

 almost ideal material for the consolidation and repair of fragile 

 bronzes. Both these techniques provide striking examples of the 

 modern kind of conservation which would have been almost impos- 

 sible to carry out using the old traditional materials. 



One of the attractive features about the use of synthetic materials 

 in the development of new methods of conservation is the fact that 

 many possess an unusual combination of chemical and physical 

 properties not met with in natural products. This obtains with 

 many of the new synthetic waxlike materials, especially the poly- 

 ethylene glycol waxes, which are produced by the polymerization 

 of ethylene oxide. The members of the series are designated by 

 numbers representing their average molecular weight, and range in 

 consistency from soft materials like Vaseline to white solids like 

 ordinary paraffin wax. Although they are like waxes in appearance, 

 they have the interesting property of dissolving in water, and are, 

 therefore, of interest in certain kinds of conservation work. One 

 of the soft waxes — grade 1500, which is composed of equal parts of 

 liquid grade 300 and a solid grade 1540 — can be used to restore 

 flexibility to leather objects that are found to be in a brittle state 

 owing to desiccation [7]. The actual procedure is very simple, as it 

 is merely necessary to immerse the object in the molten wax at a 

 temperature of about 45° C. Another problem which has occupied 

 the attention of chemists in museum laboratories for a long time has 

 been the development of a reliable method for the treatment of 

 wooden objects that are excavated from damp conditions in a so-called 

 waterlogged condition. The actual physical state of such objects 

 will be dependent upon the extent to which the ccllulosic component 

 of the wood has been degraded as the result of biochemical attack. If 

 this is far advanced, the wood may be quite soft and will have very 

 little mechanical strength. The treatment of waterlogged wood 

 involves two factors, namely, first the removal of the large excess 

 of water without causing the collapse of the weakened cell-walls, and 

 consequent warping and shrinkage of the wood, and, secondly, some 

 method for strengthening the wood so that the object can be handled 

 with safety. Various attempts were made to solve this problem, but 

 they were found to be either unreliable, limited in scope, or very slow 

 and time-consuming. However, interesting techniques based on the 

 use of synthetic materials have recently been evolved which show a 

 great advance over previous methods. The first of these depends 

 upon the use of the polyethylene glycol wax of grade 4000, employing 

 a special procedure wliich was worked out in the British Museum Re- 

 search Laboratory, Details will be found in a publication by Organ 



