598 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1962 



[8] describing the successful treatment of soft, fragile waterlogged 

 wooden artifacts from a site at the Kalambo Falls in Southern 

 Rhodesia, which were of considerable interest because they were con- 

 sidered to be wooden tools of the Lower Paleolithic period and had 

 been estimated by the radiocarbon dating method to be about 53,000 

 years old. The second method was developed at the Historisches 

 Museum in Berne; in this the material used for consolidation is a 

 special melamine-formaldehyde resin which is produced by Ciba Ltd. 

 under the trade name Arigal C. Details of the actual process have 

 been published by Miiller-Beck and Haas [9] . 



Another new synthetic material, which has been adapted to solve 

 particular problems in conservation, is N-hydroxy methyl nylon, 

 which is formed by the action of formaldehyde on nylon and is pro- 

 duced by I.C.I. Ltd. under the trade name "Maranyl soluble nylon 

 C 109/P" [10]. This dissolves in methyl or ethyl alcohol and the film 

 which is formed upon evaporation of the solvent has certain properties 

 which make it suitable for dealing with particular problems in the 

 conservation of archeological materials. One such problem is the 

 treatment of porous objects — for example, limestone carvings and 

 earthenware tablets or potsherds called ostraka used in ancient Egypt 

 for writing purposes — which have absorbed soluble salts whilst buried 

 in salty ground. TNHien such objects are exposed to fluctuating humid- 

 ity conditions, as occurs in many museums, these salts are transported 

 to the surface where they crystallize and weaken it so that decorative 

 details of carving, or the writing, may flake off. Before these objects 

 are washed in water to remove the soluble salts, it is essential that pre- 

 cautions be taken to consolidate the surface prior to washing. Since 

 the fihn of soluble nylon is, first, permeable to water, thus allowing 

 elution of the soluble salts during washing, and, second, is markedly 

 flexible so that it does not exert undue contraction on the frail surface 

 layers, it is ideally suitable for this purpose. This material has 

 already been sviccessfully used in the washing of many hundreds of 

 ostraka. It was also found, incidentally, that this soluble nylon can 

 act as an adhesive when it is necessary to employ a mobile nonaqueous 

 adhesive. Such a case arose in connection with a fragment of a 

 tempera wall-painting from a tomb at Thebes in which the paint was 

 flaking away from the ground layer. Owing to the possible risk of 

 softening the ground layer or activating soluble salts in the plaster 

 support, it was considered inadvisable to use a normal aqueous adhe- 

 sive such as glue. Instead, a warm 5 percent alcoholic solution of 

 soluble nylon was used; this proved most suitable because it has a 

 relatively low surface tension and readily flows under the detached 

 flakes of paint. Furthermore, the soluble nylon film has a distinctly 

 matt appearance, so that there is no esthetically unattractive sheen on 

 the treated areas. Other uses which have been found for this interest- 



