The cover image was created by the transcriber and is placed in the public domain.

THE PRESERVATION
OF ANTIQUITIES

Time, which antiquates antiquities, and hath an art to make dust of all things, hath yet spared these minor monuments.

(Sir Thomas Browne, Hydriotaphia, cap. v.)

A HANDBOOK FOR CURATORS

TRANSLATED, BY PERMISSION OF THE AUTHORITIES OF THE ROYAL MUSEUMS, FROM THE GERMAN OF
Dr FRIEDRICH RATHGEN
Director of the Laboratory of the Royal Museums, Berlin
BY
GEORGE A. AUDEN, M.A., M.D. (Cantab.)
AND
HAROLD A. AUDEN, M.Sc. (Vict.), D.Sc. (Tübingen)

CAMBRIDGE:
at the University Press
1905

CAMBRIDGE UNIVERSITY PRESS WAREHOUSE,
C. F. CLAY, Manager.

London: AVE MARIA LANE, E.C.

Glasgow: 50, WELLINGTON STREET.

Coat of Arms

Leipzig: F. A. BROCKHAUS.

New York: THE MACMILLAN COMPANY.

Bombay and Calcutta: MACMILLAN AND CO., Ltd.

AUTHOR’S PREFACE.

The increasing recognition of the importance of the preservation of antiquities justifies the publication of a handbook dealing with this subject. As far as I can ascertain, with the exception of a short article[1] for which I am myself responsible, only one work has appeared which covers the whole field—the “Merkbuch[2]” prepared by Dr Voss at the request of the Government. But as this book only gives a selection of the known methods of preservation, the need of a more comprehensive publication will scarcely be denied.

In spite of my ten years’ experience in the special Laboratory of the Royal Museums and the frequent opportunities of learning the methods in use elsewhere, which the journeys and correspondence arising out of my duties have given me during this period, I do not feel competent to produce a review of these various methods which will be at once exhaustive and sufficiently critical. There are several reasons for this. In the first place the individual methods have been but rarely published, and even then through the most varied literary media; often they are only casually mentioned in articles dealing with anthropological or historical subjects. On the other hand, the value of an object to be dealt with may prohibit an attempt at treatment, the success of which is not assured. My own experience has been gained by trials with objects chiefly from the Egyptian section, but also to some extent from the Antiquarian and Numismatic departments of the Royal Museums.

This deficiency can only be remedied by a work such as that now offered to the public, and it is to be hoped that this handbook will stimulate the Curators of State, Municipal and Societies’ Collections, as well as private collectors and others interested in the subject, to make public their further experiences in this field of archaeology. I take this opportunity, therefore, of expressing the hope that I may receive other communications bearing upon the subject and may thus perhaps at some future date be able to produce a more complete work.

In using the book it will be noticed that for the proper understanding of the first portion, which deals with the causes of destruction, a certain amount of chemical knowledge is assumed. In the second portion, however, the methods of preservation are treated from a more elementary standpoint, and the simple apparatus and manipulations required are so described that the treatment may be readily carried out by those who are unfamiliar with chemical methods.

In conclusion, I take this opportunity of expressing my thanks to all those who have given their help, and especially to Dr Otto Olshausen for his continued interest in the work of the Museum Laboratory and in the production of this handbook. Especially am I indebted to his extensive knowledge of anthropological literature for many references which would otherwise have escaped my notice.

TRANSLATORS’ PREFACE.

Dr Rathgen has, in his preface, stated the aim of this handbook, and it is with a desire to further this aim that we have prepared an English translation.

Claiming but limited experience in this field of research we have only added such explanatory notes as seem in some way to bear upon the subject or likely to be useful in a handbook of this kind (viz. the method of taking squeezes, Appendix A, and a few footnotes which are signed and enclosed in square brackets). We take this opportunity of thanking Dr Rathgen for his interest in our undertaking, for his kindness in supplying much additional matter which did not appear in the German edition, and also for the loan of the blocks for Figs. 22 and 23. Figs. 7, 9-12, 30-33, and 37, are from photographs of objects treated by ourselves.

Our thanks are especially due to Dr W. A. Caspari, of the National Physical Laboratory, for his invaluable help in the revision of the translation, and for his advice and suggestions in reference to the more technical aspect of the work.

York,
December 1904.

CONTENTS.

	PAGE
Literature	xiii
Part I.
The changes undergone by antiquities in earth and in air	1
Limestone and clay	2
Iron	7
Bronze and copper	15
Silver	49
Lead	53
Tin	53
Gold	53
Glass	54
Organic substances	54
Part II.
The preservation of antiquities	56
i. Preservation of objects composed of inorganic substances
a. Limestone	56
b. Marble and alabaster	74
c. Earthenware	74
d. Slightly baked or unbaked clay	81
e. Fayence	86
f. Stucco and Nile-mud	87
g. Sandstone and granite	87
Appendix: Cement for earthenware. Restorations	87
h. Iron	89
1. Methods of preserving objects of iron without removal of the rust	89
2. Preservation by steeping and subsequent impregnation	92
3. Preservation by removal of the rust	102
4. Preservation of medieval iron objects	119
i. Bronze and copper	120
A. Methods of impregnation	122
B. Preservation by reduction	125
Reduction of oxidized copper coins	140
Cleaning copper coins with melted lead	143
C. Preservation by exclusion of air	144
Appendix: Method of bringing out worn lettering upon coins	146
j. Silver	148
k. Lead and tin	149
l. Gold	150
m. Glass and enamel	151
ii. Preservation of organic substances.
n. Bones, horns, ivory	151
o. Leather	152
p. Textile fabrics, hair	153
q. Feathers	154
r. Papyrus	154
s. Wood	156
1. Dry preservation	156
2. Preservation in liquids	159
Protection against wood-worms, etc.	160
Preservation and cleaning of coloured objects of wood	161
t. Amber	162
Care of antiquities after preservative treatment	162
Concluding remarks	164
Appendix A. Method of taking squeezes of inscriptions	166
Appendix B. Zapon	168
Index	171

ILLUSTRATIONS.

FIG.		PAGE
1.	Limestone block with well-preserved surface	3
2.	Limestone block with pitted surface	3
3.	Limestone block showing destruction of surface	4
4.	Potsherd showing saline efflorescence	5
5.	Pottery showing sodium nitrate efflorescence	6
6.	Portion of horse-trappings showing blue and green patina	35
7.	Head of Osiris showing advanced condition of warty patina	38
8.	Etruscan mirror showing warty patina	40
9.	Bronze figure showing destructive patina	42
10.	Bronze figure showing destructive patina	43

11.	The same after treatment (Finkener’s method)	44
12.	The same after treatment (Finkener’s method)	45
13.	Gay-Lussac’s burette	62
14.	Air-pump fixed to water-tap	68
15.	Apparatus for impregnation by extraction of air	69
16.	Assyrian clay tablet showing incrustation	79
17.	The same after treatment	79

18.
19.	Assyrian clay tablet before and after treatment	80
20.	Assyrian clay tablet before and after treatment	80
21.

22.	Babylonian clay cone before and after treatment	82
23.	Babylonian clay cone before and after treatment	83
24.	Water-bath for iron objects	94
25.	Iron sword treated by Blell’s method	108
26.	Iron spear-head treated by Blell’s method	109
27.	Iron fibula treated by Blell’s method	109
28.	Application of Krefting’s method	111
29.	Iron spear-head treated by Krefting’s method	112
30.	Iron pin before and after treatment by Krefting’s method	113
31.	Iron pin before and after treatment by Krefting’s method	113

32.	Iron object before and after treatment by Krefting’s method	114
33.	Iron object before and after treatment by Krefting’s method	114
34.	Piece of iron sword-blade with inscription revealed by Krefting’s method	116
35.	Iron sheath after treatment by combination of Blell’s and Krefting’s method	117
36.	Hammer-heads for removal of bronze incrustations	120
37.	Osiris showing cracking and destructive patina	123
38.	Boeotian bridle showing cracked patina	124
39.	Bronze bull showing warty patina	132
40.	The same after reduction by Finkener’s method	133
41.	Bronze axe-blade before treatment by Finkener’s method	134
42.	The same after treatment by Finkener’s method	135
43.	Reverse side of same after treatment	136
44.	Dagger-sheath before treatment by Finkener’s method	137
45.	Dagger-sheath after treatment, showing design	137
46.	Roman coins before treatment by Krefting’s method	142
47.	Roman coins after treatment by Krefting’s method	143
48.	Method of mounting objects in air-tight damp-proof cases	145

LITERATURE.

Aarböger for nordisk Oldkyndighed og Historie, udgivne af det kongelige nordiske Oldskrift-Selskab. Copenhagen.

Aarsberetning fra Foreningen till norske Fortidsmindesmaerkers Bevaring. Christiania.

Annalen der Chemie und Pharmacie. Edited by Wöhler, Liebig and Kopp. Since 1873: Liebig’s Annalen der Chemie.

Antiquarisk Tidsskrift, udgivet af det kongelige nordiske Oldskrift-Selskab. Copenhagen 1843-63.

Archaeological Journal. London.

Atti della Reale Accademia dei Lincei. Rome.

Berg- und hüttenmännische Zeitung. Leipzig.

Bibra, E. v. Die Bronzen und Kupferlegirungen der alten und ältesten Völker. Erlangen 1869.

Bibra, E. v. Ueber alte Eisen- und Silberfunde. Nürnberg and Leipzig 1873.

Bischoff, C. Das Kupfer und seine Legirungen. Berlin 1865.

Blätter für Münzkunde. Hannoversche numismatische Zeitschrift. Edited by H. Grote. Leipzig.

Chemiker-Zeitung (Dr G. Krause). Cöthen.

Chemisches Centralblatt (Arendt) Hamburg and Leipzig.

Christiania Videnskabs-Selskabs Forhandlinger. Christiania.

Comptes rendus hebdomadaires des séances de l’Académie des sciences, publ. p. les secrétaires perpétuels. Paris.

Dingler’s Polytechnisches Journal. Stuttgart.

Finska Fornminnesföreningens Tidskrift. Helsingfors.

Finskt Museum. Finska Fornminnesföreningens Månadsblad. Helsingfors.

Friedel, E. Eintheilungsplan des Märkischen Provinzialmuseums der Stadt Berlin. 6th issue. Berlin 1882.

Graham-Otto’s Ausführliches Lehrbuch der Chemie. 5th Edition. Anorgan. Chemie von H. Michaelis. Brunswick 1878-89.

Hauenstein, H. Die Kessler’schen Fluate. 2nd Edition. Berlin 1895.

Journal für praktische Chemie. Edited by Erdmann. Leipzig,

Journal of the Chemical Society. London.

Keim, A. Technische Mittheilungen für Malerei. Munich.

Kongl. Vitterhets Historie och Antiqvitets Akademiens Månadsblad. Stockholm.

Kröhnke, Chemische Untersuchungen an vorgeschichtlichen Bronzen Schleswig-Holsteins. Dissertation. Kiel 1897.

Layard. Discoveries in the ruins of Nineveh and Babylon. London 1853.

Lepsius, C. R. Denkmäler aus Aegypten und Aethiopien. Berlin 1849-59.

Lueger, O. Lexikon der gesamten Technik. Stuttgart 1894.

Merkbuch, Alterthümer aufzugraben und aufzubewahren. Herausgeg. auf Veranlassung des Herrn Ministers der geistlichen, Unterrichts- u. Medizinal-Angelegenheiten. 2nd Edition. Berlin 1894.

Mittheilungen der naturforschenden Gesellschaft in Bern. Bern.

Mittheilungen aus der Sammlung der Papyrus Erzherzog Bainer. Vienna 1887-1889.

Morgan, J. de, Fouilles à Dahchour Mars-Juin 1894. Vienna 1895.

Muspratt’s theoretische, praktische u. analytische Chemie. 4th Edition. Brunswick 1883.

Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefakten-Kunde, edited by K. C. von Leonhard and H. G. Bronn. Stuttgart.

Polytechnisches Centralblatt. Leipzig 1835-75.

Polytechnisches Centralblatt. (Geitel.) Organ der polytechn. Gesellschaft zu Berlin. Berlin 1888.

Prometheus, edited by Dr O. N. Witt. Berlin.

Publications de la société pour la recherche et la conservation des monuments historiques dans le grandduché de Luxembourg. Luxemburg.

J. J. Rein, Japan. Nach Reisen und Studien im Auftrage der Königl. Preuss. Regierung. 2 Vols. Leipzig 1881-1886.

Revue archéologique, publiée sous la direction de MM. A. Bertrand et G. Perrot. Paris.

Schliemann, H., Ilios. Leipzig 1881.

Simon, E., Ueber Rostbildung und Eisenanstriche. Berlin 1896.

Sitzungsberichte der Alterthumsgesellschaft Prussia in Königsberg.

Verhandlungen der Berliner Anthropologischen Gesellschaft. Berlin.

Verhandlungen des Vereins zur Beförderung des Gewerbefleisses in Preussen. Berlin.

Zeitschrift für Numismatik. Edited by A. v. Sallet. Berlin.

Zeitschrift für anorganische Chemie.

Zeitschrift für Ethnologie. Berlin.

PART I.
THE CHANGES UNDERGONE BY ANTIQUITIES IN EARTH AND IN AIR.

The greater number of those objects of antiquity which are composed of inorganic materials, such as limestone, earthenware, and metals, owe the commencement of any alteration in their character to the situation in which they are discovered, since they are buried in ground which has been at some period damp or wet, and has contained, moreover, salts soluble in water. Amongst these salts the most usual is sodium chloride (common salt), but this is mostly accompanied by potassium chloride, potassium sulphate, magnesium chloride, and calcium sulphate; in short, by those soluble salts which are found in sea-water. In the fine pores of Egyptian antiquities, especially, such salts occur, and their presence is readily explained by the fact that the land of Egypt was originally a sea-bottom.

The presence of salt in the soil of Egypt has been known for a considerable period. Thus Karabacek[3], quoting from Volney’s “Travels in Syria and Egypt” (Jena, 1788, I. p. 13):

“Wherever one digs one finds brackish water containing soda, sea-salt, and a small quantity of saltpetre. Indeed, when a garden has been flooded for irrigation purposes, crystals of salt make their appearance on the surface after the water has evaporated or has been soaked up by the soil.”

In the dry climate of Egypt, objects saturated with salt keep better after their removal from the ground than in our climate, where the variations in the temperature and in the hygroscopic condition of the air produce a partial deliquescence in wet weather, and in dry weather a re-formation of crystals. The continued alternation of these processes gradually loosens the surface of limestone or earthenware, or induces certain chemical changes in objects of metal and in both cases leads to their destruction.

Limestone and Clay.

The series of changes are particularly well illustrated by the Egyptian grave of Meten[4], the stones from which are now in the Royal Museum in Berlin. The three illustrations here given show: (1) an undecayed block of limestone, (2) a block with pitted surface, and (3) a block the surface of which was formerly covered with hieroglyphics, but which is now totally destroyed by flaking. The blocks of the latter kind were found in the lowest layer, or lowest but one, while those blocks which were above were the best preserved. As the amount of salt present scarcely varied, these specimens offer a striking illustration of the greater influence of moisture in the deeper soil than at the higher levels.

Fig. 1.
Limestone block, surface well preserved.

Fig. 2.
Limestone block with pitted surface.

The Project Gutenberg eBook of The preservation of antiquities

THE PRESERVATION OF ANTIQUITIES

AUTHOR’S PREFACE.

TRANSLATORS’ PREFACE.

CONTENTS.

ILLUSTRATIONS.

LITERATURE.

PART I. THE CHANGES UNDERGONE BY ANTIQUITIES IN EARTH AND IN AIR.

Limestone and Clay.

THE PRESERVATION
OF ANTIQUITIES

PART I.
THE CHANGES UNDERGONE BY ANTIQUITIES IN EARTH AND IN AIR.