EGYPTIAN TREASURES.

New Zealand Herald, Volume LX, Issue 18357, 24 March 1923, Page 11

EGYPTIAN TREASURES.

WORK OF THE EXPERTS.

THE TRIUMPHS OF SCIENCE. (The Times' World Copyright, by Arrangement with the Earl of Carnarvon.) .. 'BY ALFEED < LUCAS • (Director of the Chemical Department of '■';• the Egyptian Government.) ,: Each year for>' about -four months (December to March) the quietness of the Valley of the Kings at Thebes is .disturbed by ' sightseers and their attendant guides, drivers and donkey boys. :•■•.. This season (1922-23) there has been a further invasion, but as the invaders are, for the most part, hidden in old unfinished tombs 'at the head of the valley, their presence is largely unknown and unsuspected by the casual visitor. The invaders are the staff that Mr. Howard Carter has gathered [together to help in the work necessitated by the discovery of . the tomb of Tutenkhamun. This staff comprises Messrs. A. H. Calender, R. Burton, A. C. Mace, A. Lucas W. Houser, and L. Ft Hall, with occasionally others, such as Dr Alan H. Gardiner, together with watchmen, guards, policemen, carpenters and servants. The work to be done by the experts includes numbering and photographing the objects in situ, making a plan of the tomb showing the exact position of every article, and removing the objects temporarily to another tomb used as a laboratory and workshop, Where they are described and where they undergo cleaning and preliminary preservative treatment. After this they will be carefully packed, transported about six miles to the river, loaded on to a steamer, and sent to Cairo, where, after unloading and unpacking at the Cairo Museum, they will be described in detail for the purposes of the final report, treated again if required, and then placed on exhibition. All this will naturally take a considerable time. The work, (too, is rendered more difficult by having to be done in the desert, away from all modern conveniences. Treating the Exhibits. The section of the work on which the writer is engaged, together with Mr. C. A. Mace (associate curator, Metropolitan Museum of Art New York), is the cleaning and preliminary treatment of the objects, and this, therefore, alone will be described. In many large museums such as the British Museum, the South Kensington Museum, the museums at New York, Berlin, Copenhagen, and Stockholm, various methods of treating exhibits are employed, but -these methods are not generally known, and have never been fully explained!. There is only one book on the subject, a German one, which has reached a,second edition, and of the first edition of which there is an English translation. There are also short papers in various scientific journals, and lately there has been published „ a small but very helpful pamphlet describing the methods and resultfs of the work being carried out by Dr. Alexander Scott at the British Museum. Some field methods of treatment have been described by Professor Flinders Petrie. Until recently it has not been sufficiently realised that the work of cleaning and preserving museum specimens is highly scientific and largely chemical, but, fortunately, this is now becoming more generally recognised. The underlying principles of the subject are. first, • to ascertain the composition of the object to be dealt with; secondly, to determine the cause of any deterioration (which is generally largely the result of chemical action) ; and, thirdly, to remove the cause of the damage and to restore the object, as far as possible, to its original condition, which, as a rule, can only be done by appropriate chemical treatment. This sounds simple. When one knows how to do it, it is simple; like everything else, nevertheless, it demands special training and ' experience. ■\ . ■'-" - The first stage of any treatment is to remove'the cause of any disintegration; thus, if the object is damp, it must be dried; if it contains salt, this must be dissolved out'; if it is disfigured by calcareous concretions, as is sometimes, the case, thesejmav generally: be got rid of by means; of dilute acid: but indiscriminate drying, washing, or the,use,of acid will often do more harm than good, and it ig only ; bv a knowledge of the chemical and physical properties }of materials that the best results can be attained or even that disaster can be avoided. 1 , ''■"%y.:.S Atmospheric Influences. ; -Suitable treatment, properly applied, enhances considerably the value of an object, but any error, either in the nature or method of the treatment used, may do incalculable damage. , There are, and can be, no 'fixed rules for treatment, since the nature of the objects and the conditions that have caused the damage are so various. :'.' Each article must be made; the subject of special study. There are, of. course, general principles which can be used a* guides,; but these can only be successfully) interpreted and applied by those having chemical knowledge, and also considerable experience in delicate manipulation. < Srice most museum exhibits are j: sub ject-ed to an atmosphere quite unlike, ahc generally much worse than, that for whicl: they were "originally intended, . and ar atmosphere too frequently saturated wit! moisture and containing noxious v?gases and even dilute acids, a secondary stag* of treatment to enable . the exhibits tc withstand the deleterious conditions of >'t modern city is frequently necessary. v This secondary treatment generally consists ii coating the objects with something thai will render them impervious to' atmos pheric influences. .'■>"''• ,/ Five Glasses of Objects. , As any detailed scientific explanation o the methods of treatment employed 'am the reasons': for their adoption would b< out of place here, nothing beyond a brie , non-technical description will be given The objects ■ found may be divided roughly into five main classes— (a) metals (b) » wood, (c) alabaster and faience, (d textile fabrics, and (e) leather. •'*.,.:' Metals.—These comprise gold, silver and bronze. ~ So far as can be seen a present, these are all in fairly good con dition. ■'■ In -several instances gold orna mentation which was merely tarnished and which it was desired should show u] well when the object was photographed has been cleaned by gentle rubbing witl fcoft linen and soap and water, and ii some cases with a little ammonia." Th< silver and bronze have not yet beei treated.' ■'■ '■ - ' /■'' -■:.;•:' Wood. —Some '* of this ■ is- ' simply painted, but- the greater part is covare< with a thin coating of . plaster), (gesso) which is painted: or gilt. : - Owing "to-th wood I having dried and shrunk, the pain or gesso blisters and peels v off. If th damage is slight, the best; treatmentafter removing dustis "to fill up an; blisters with paraffin wax by introducipi a strong warm solution of wax dissolvei in benzine underneath the blister b; means of a pipette. When cold,' an* when the benzine has evaporated, "th wax becomes solid. Any loose pieces c

paint or gesso are then replaced and stuck oh with a strong solution of celluloid in amyl acetate, after which the whole surface is sprayed with a dilute solution of celluloid dissolved in a mixture of amyl acetate and acetone. -If the damage is considerable or if the difference of temperature and humidity ; causes the object when taken out of "the "tomb to become worse, as sometimes : \ happens, then the whole :is coated with ; paraffin wax, which is applied in the molten state" and penetrates '■ and > saturates the .wood, any excess .wax - being afterwards removed by heat. "■'■'■• v? \'.' : " : :y . " », • iV; Alabaster . and , Faience.—These will probably require very little treatment beyond washing with water. Textile Fabrics. —Some of these have entirely perished, others are in a very friable condition and partly in holes, and only. a few are in ; good condition. To strengthen fabrics of this.;kind, the best material '' is a solution: of cellulose acetate dissolved in acetone, ;or a solution of celluloid dissolved in a mixture of amylacetate and acetone. : This is applied >by means of a spray. - ; -,'-.' . ' Leather.Most of (this has perished and has. become black, brittle, ..and\resin-ous-like, and breaks into small fragments when touched. '; Experiments are now being made, to soften this leather. ; ; The substances being tried include castor oil, vaseline, and lanolin©* i ' ■ ■*>