Drayman, T. a Perspective History Conservation Archaeoloical Cooper. 1994

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JAIC 1994, Volume 33, Number 2, Article 6 (pp. 141 to 152)

A PERSPECTIVE ON THE HISTORY OF THE

CONSERVATION OF ARCHAEOLOGICAL

COPPER ALLOYS IN THE UNITED STATES

TERRY DRAYMAN-WEISSER

ABSTRACTThis paper reviews the history of the treatment of archaeological copper

alloys (bronzes) in the United States using unpublished reports and correspondence in

the files of the Walters Art Gallery, Baltimore, personal interviews, and early andselected later publications. Correspondence around the turn of the century documents a

concern about the devastating effects of bronze disease and traces the early history of

the understanding of its causes and methods for combating it. Early publications by

Fink and Eldridge (1923, 1925), Garland and Bannister (1927),Nichols (1930), Lucas

(1932), Plenderleith (1934, 1956), and Ternbach (1949) demonstrate the development

and use of cleaning techniques for severely corroded bronzes. The role that advances in

analytical techniques and scientific instrumentation played in the evolution of approach

and philosophy for treatment of archaeological bronzes is discussed. A major effect

cited is that the goal of treatment for archaeological bronzes has changed from

attempting to return an artifact as closely as possible to its original form to preserving

the patina and burial accretions for research and study.

1 INTRODUCTION

The conservation of severely corroded copper alloys (the historical term bronze will

be used hereafter for the more accurate term copper alloy) and the stabilization of

active bronze disease are two of the most difficult problems facing the archaeological

conservator. A survey of the conservation literature reveals that these problems are not

new and that treatment methods and philosophies have changed during the past century.

This paper looks at the evolution of the treatment of ancient bronzes in the United States

as reflected in correspondence, unpublished documents, and selected publications found

in the archival records and library of the Walters Art Gallery, Baltimore. A review from

this perspective seems fitting, since Henry Walters, who built the Walters Art Gallery in

1904, was one of America's foremost collectors of ancient bronzes, and he demonstrated

a deep concern for their preservation. His concern was perpetuated when, at his death in

1931, his museum was bequeathed to the city of Baltimore, and within three years a

technical laboratory was created that established the treatment of bronze disease as

one of its first research priorities. Throughout the history of what is now the Walters

Division of Conservation and Technical Research, the conservation of bronzes has

remained a high priority.


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This paper also attempts to address the role that science has played in changes in

treatment methods and goals for bronze over time. Surprisingly, although the scientist

was central to the development of early treatments for ancient bronzes and to advancing

understanding of the corrosion processes, there is still no permanent cure for bronze

disease that can be considered safe for the artifact. However, it should be

acknowledged that science has brought a profound change in the philosophy oftreatment of archaeological materials. By demonstrating what can be learned through

examination and analysis of the object with its burial accretions, the scientist has caused

a re-evaluation of treatment goals. The emphasis has moved from restoring an object as

closely as possible to its original state to using an object as a primary research document

for learning as much as possible about its historical context, technology, use, and

environment. This emphasis prevails even in classical archaeology collections that have

unprovenanced materials for which the composition of the metal, the encrustations, and

residues in the patinas may be the only clues to original context and association with

other related objects.

The scope of this paper is limited largely to observations based on source materialsfound at the Walters Art Gallery. Although it does not provide a comprehensive history

of the treament of ancient bronzes, it presents material that might not otherwise be

readily accessible. One of the primary values of such a review lies in enhancing an

understanding of the effects of earlier treatments and the possible consequences of those

we carry out today. It is hoped that this paper will encourage other conservators to

review their files and add to the body of knowledge on this subject.

2 A HISTORICAL REVIEW

Research for this review began with an examination of the archival materials in the files

of the Walters Art Gallery's conservation laboratory, where pertinent correspondence

was found dating to 1910. A look at a week's correspondence in December of that year

between Henry Walters (fig. 1), two dealers, and the newly appointed director of the

Metropolitan Museum of Art, Edward Robinson (an archaeologist by training),

demonstrated Walters's concern for his bronzes. It also provided a glimpse at the

understanding of and treatment for bronze disease at the beginning of this century.


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Fig. 1. Thomas C. Corner, Portrait of Henry Walters, 1938, oil on canvas. 45 38 in. Collection of

the Walters Art Gallery, acc. no. 37.1682.

On December 6 (Walters correspondence), Walters wrote to Mr. Canessa, a New York

dealer, saying:

I have two bronzes which came from Egypt and which have developed a corroding

canker. Can you tell me what I should do to stop the eating away of these bronzes? One

of these passed through the hands of Andr1 in Paris, and I am very surprised that the

canker should have broken out again.

On December 7 (Walters Correspondence), Canessa answered that he had found no

radical means of stopping a corroding canker which affects especially Egyptian

bronzes. He added that the most lasting method he had found was to rub wax with a

small brush on the spot each time the spot reappeared.

On December 8 (Walters Correspondence), Walters wrote to Robinson passing on

Canessa's advice and asking for information on Robinson's use of lime in display

cases (Walters may be confused here since Robinson's reply describes the use of the

highly hygroscopic potassium hydroxide, not lime). He also corresponded with another

dealer, Mr. Kelekian, then in Paris, saying:

I am sorry to report that an ugly corroding canker has developed on the very fine littlesitting figure of The Athlete, on the side of the face, and it has already made some


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inroads. Can you tell me any treatment I can give the bronze which will stop this? The

same trouble I find on the bronze Asp which came from Mitrahene, and the

Metropolitan Museum tell [sic] me that much trouble of this nature has been found

with the bronzes discovered at that place. They consider it due to some composition

used in making the bronze.

On December 12 (Walters Correspondence), Robinson responded to Walters's letter of

December 8. He warned:

As I told you ancient bronzes require constant watching, whatever treatment they

receive to begin with. The main thing seems to be to keep the cases in which they are

exhibited perfectly dry after their treatment, and for this purpose we use hydrate of

potassium in sticks. These are placed in the bottom of the case in a small cup. The

moisture in the air gradually dissolves the sticks, and they should be renewed as fast as

they are dissolved. With us they last from three to six months.

Robinson also enclosed a translation of Andr's description of the method by which hetreated diseased bronzes, which they had been using with success at the Metropolitan

for two years. According to the translation supplied by Robinson, Andr's method was:

(1) to dry out the bronzes for a few days in an oven with jewelers' sawdust; (2) to

remove the oxide with a needle; (3) to apply a drop of Palestine bitumen; and (4) to

wipe off the excess after it had been given time to penetrate.

Correspondence in the files dated 10 years later indicates that Walters was still actively

pursuing information on the treatment of bronzes. On May 4, 1923, he filed at the

Walters Art Gallery a typewritten preliminary report titled, Efficient Method for

Restoration of Antique Bronzes Badly Corroded or Crusted Over, written for Robinson

by Colin G. Fink, professor of electrochemistry at Columbia University, assisted by

Charles H. Eldridge (Fink and Eldridge 1923). The purpose of the study was to find a

method for restoring badly corroded ancient bronzes, to determine the cause of bronze

disease, and to find a simple means for combating it. However, the report, which

covers the first four months of work, indicated that the restoration of surfaces was the

primary thrust of the project. Fink and Eldridge's report included a discussion of the

drawbacks of three treatments in use at the time: (1) the popular method of mechanical

cleaning combined with dipping in an acid bath, which they thought too drastic; (2)

Friedrich Rathgen's (1905) electrolysis in potassium cyanide solution, which, although

an improvement, caused pitting; and (3) the formula of AlexanderScott (1921, 1923) of

the British Museum for chemical cleaning, which led to pitting and loss of detail,although they felt it would be satisfactory for high silver alloys.

Fink and Eldridge discussed in detail their own electrolytic method whereby the metal

compounds contained in the object's crust were reduced to metal, which was

consolidated and hardened while other constituents such as carbonic acid, chlorine, and

sulfur were removed. Their method involved an electrolytic bath with the object as

cathode packed into fine clean silica sand contained in a porous cell. The cell was

placed in a larger container and filled with a 1% solution of sodium hydrate (sodium

hydroxide). A low density current was passed through the cell for two weeks or more.

They claimed that details were revealed, there was no pitting, and completely corroded

sections of the objects were reduced back to metal.


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In 1925, Fink and Eldridge published their first report based on the above research. In

the introduction, Edward Robinson made an interesting statement that reflects an often

heard, but erroneous, belief(Robinson 1925). He stated that one diseased specimen

in a show-case may and frequently does infect others. Robinson also called for the

establishment of a national laboratory to assure the highest-quality scientific treatment

of artifacts for museums, private collectors, and dealers.

Fink and Eldridge began their book by noting that past treatments had been haphazard

and usually secret and that therefore there are few references that give details on

cleaning and restoring methods:

It has been unfortunate that men who undertook to clean, repair, and restore usually had

no artistic or scientific knowledge or appreciation but were primarily interested in the

sum to be realized upon completion of the cleaning.

They also stated that the restorer almost always tried to bring out details in design and

yet not make the object appear to be of recent origin.

Fink and Eldridge set an ambitious treatment goal for themselves:

A really serviceable and generally applicable method of restoration must not be

dependent upon differences in composition of the alloy or of the incrustation or patina,

but must work well with all; and the resultant product must not leave any doubt in the

mind of the restorer that perhaps some other method might have been more satisfactory.

The object of Fink and Eldridge's investigation was to remove the crust and at the same

time restore or preserve intact any detail of shape, design, engraving, tool mark, or other

signs of workmanship remaining on the specimen.

In support of the uniqueness of their treatment, Fink and Eldridge reviewed the

literature and pointed out the differences between their electrolytic method and that of

others (Finkener 1905; Frisch 1904; Rocchi 1920). They also mentioned two booklets

written in 1921 and 1923 by Alexander Scott, who directed the laboratory at the British

Museum after its founding in 1919, and stated that Scott used ordinary chemical

methods, not electrolytic treatment, for removing the crust.

The main differences between the Fink and Eldridge electrolytic method proposed in the

1923 preliminary report and the method published in their 1925 book were (1) they nolonger recommended packing the object in sand except if there was a danger of the

object falling apart; (2) they increased the concentration of the electrolyte from 1% to

2%; and (3) they shortened the length of time required to complete the reduction from

several weeks to three or four days.

They dealt with bronze disease in a separate section of the book. Although they did

not know how bronze disease started at any particular spot, they stated that the cause

was the presence of a trace of chloride and that the corrosion was primarily electrolytic.

For stabilization treatment they recommended their electrolytic method, followed by

coating with a mat cellulose acetate lacquer, renewing the coating at least every four

years.


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On patinating restored bronze surfaces, Fink and Eldridge stated:

The inevitably unlovely appearance of such bronzes after they have been through the

treatment for the removal of the ugly crust is a matter of common experience no matter

what the method for the removal of the crust has been. Dealers as well as museum

authorities, recognizing the fact, have sought to overcome it by supplying an artificialpatina, often deceptively successful. There is no doubt that a large percentage of the

ancient bronzes in public and private collections have been artificially patinated.

They felt that it was allright to repatinate if it did not damage the bronze and if the

patina could be readily removed if desired. One must wonder how they defined

damage since they reported the best repatination results from a rather aggressive

simultaneous attack of ammonia and acetic acid gas.

Fink and Eldridge concluded that they met their stated goal. They declared that their

electrolytic method is of very general application and could be used with absolute safety

in practically all cases of restoration. On April 15, 1925, theNew York Timesproclaimed in headlines, misquoting the name of the treatment, Electric Acid Bath

Restores Bronzes and Exposes Fakes. In smaller print it added, Exhibits in

Metropolitan Museum Now are Undergoing the Treatment. It is easy to see why

everyone was so excited about the electrolytic treatment if one compares the before and

after treatment photographs of an Egyptian bronze from the Walters collection (figs. 2a

andb).

Fig. 2a. Detail,Isis Nursing the Child Horus, Egyptian, Ptolemaic period (33230 B.C.), bronze, 7 in.Collection of the Walters Art Gallery, acc. no. 54.792. Before electrolytic treatment.


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Fig. 2b. Detail,Isis Nursing the Child Horus. After electrolytic treatment by Harold Ellsworth, 1936.

Soon after the publication of Fink and Eldridge's book, a conflicting view on

appropriate treatment of ancient bronzes appeared. At the death of Major Herbert

Garland, superintendent of laboratories at the Citadel in Cairo, his notes were compiled

and published (Garland and Bannister 1927). Garland recommended mechanical

cleaning with a chisel-ended hammer and avoiding immersion in acid or other liquid.

He added that mechanically cleaned bronzes were less likely to corrode again,

especially if not handled with naked fingers and if impregnated with wax immediately

after removal of the crust. If the bronze was not solid, he recommended the use of

chemical or electrochemical methods. Garland did mention that German museums were

using electrolysis with potassium cyanide and that the leading German authority,

Rathgen, painted on Zapon, a solution of nitrated cellulose, after treatment. Garland

warned against the inflammability and decomposition of nitrocellulose to liberate free

acid. He also implied, as Robinson had, that bronzes can contaminate each other. He

wrote, It is advisable to keep metal objects separate from one another in collections, inorder to prevent decay being communicated, and lamented, This is not always done in

our museums, some of which are very crowded.

Fink and Eldridge continued to have a major impact on the treatment of bronzes in the

United States, although Eldridge's name appears to have been dropped in many later

publications and now will be dropped here. Henry W. Nichols (1930), associate curator

of geology at Field Museum, Chicago, recommended the Fink electrolytic treatment and

advised against even the most minor changes in the method. Nichols had begun to use

Fink's method in 1925 to treat the Egyptian collection and between 1926 and 1929 had

treated 360 bronzes from Egypt and Mesopotamia. In the foreword to Nichols's book,

Berthold Laufer, curator in Field Museum's Department of Anthropology, pronouncedthat these objects had been returned to their original forms and that In each and every


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case the objects have obtained a new lease on their lives and are permanently

preserved (Laufer 1930). He added, The advantages accruing to archaeology from this

method cannot be overvalued and must be acknowledged with a deep sense of

gratitude. Nichols noted that the technique had two disadvantages: (1) special

equipment is needed; and (2) it requires close supervision by a man skilled in handling

antique bronzes and by a skilled chemist. He also emphasized the need to divide thelabor between the chemist who does the electrolysis and the restorer who treats the

surface afterward.

Nichols described in detail what he called cement copper slime, a form of dark,

loosely adhering redeposited copper metal that forms on the surface of the bronze

during the electrolytic treatment. He noted that this cement copper could be easily

removed but is often left on the bronze intentionally to fill in the pits in the surface and

to enhance the formation of a patina after the treatment. However, he warned of the

possible development of a thin film of adherent bright metallic copper in the position

formerly occupied by the original surface of the bronze. He was not certain why this

film formed, and he acknowledged that it was difficult or impossible to remove.

Although Nichols strongly supported the use of Fink's electrolytic treatment, in the

section of his book about malignant patina he described a chemical technique

developed at Field Museum. The treatment, which was only for bronze disease

confined to the surface, involved the application of a dilute solution of sulfate of silver

to the affected areas. At the time of publication he could not yet state whether this

treatment led to permanent stabilization.

The Fink electrolytic technique was also being employed in the 1930s at the Walters Art

Gallery by the chemist, Harold Ellsworth. However, correspondence in the Walters files

shows that a problem began to arise with some objects a few years after treatment.

Elisabeth Packard, then a conservator at the Walters, wrote to George Stout at the Fogg

Museum in January 1940 asking his advice about several ancient bronze statuettes that

had been electrolyzed by the Fink method in 1936 (Walters Correspondence). These

objects had developed a blue-green excrescence in areas that did not correspond to

formerly active areas. Stout spoke with his colleague Rutherford John Gettens about the

problem, and Gettens examined a few bronzes at the Fogg that he had treated

electrolytically in 1933 or 1934 (Walters Correspondence). He discovered that they, too,

had broken out with a blue-green, powdery deposit. He analyzed the material from one

of the Walters bronzes and found it to be mainly copper carbonate.2 The blue-green

deposit was removed from the Walters bronze, and the object was soaked in changes ofdistilled water to remove residual chemicals thought to be causing the problem.

However, in 1980, the same Walters bronze broke out again with a blue-green product.

Another bronze in the collection that had been electrolytically treated in 1936 also

recently broke out (figs. 3a, 3b). The product has not yet been analyzed.


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Fig. 3a.Apis, Bull of Memphis, Egyptian, Late Dynastic or Late Period 663332 B.C., bronze, 7 6 in.Collection of the Walters Art Gallery, acc. no. 54.418. After electrolytic treatment by Harold Ellsworth,

1936.

Fig. 3b.Apis, Bull of Memphis. Disfigured by a recent effluorescence of a blue-green product, 1987.

British publications on the treatment of antiquities became popular additions to the

library at the Walters conservation laboratory and very likely would have been found on

the bookshelves of other American conservators. These publications presented a variety

of possible treatments for bronzes. Alfred Lucas (1932), chemist in the Department of

Antiquities in Egypt, favored chemical treatments. For the treatment of bronze disease

he recommended sodium sesquicarbonate. To treat heavy corrosion he stated that the

whole patina must be removed, and he preferred sulfuric acid for this procedure. He

mentioned electrical treatmentsincluding Fink's, among othersbut he did notappear to encourage their use over chemical methods. He stated that the aim in

cleaning antique objects should be to restore, as far as possible, the original appearance

of the object.

Harold Plenderleith (1934) made a passing reference to the use of the electrolytic

method on iron, concluding that it may on occasion prove useful, but he did not

recommend it in his section on treatment of bronzes. (He did, however, include it in his

later publication [Plenderleith 1956].) He preferred electrochemical treatment with zinc

and caustic soda, sulfuric acid, or citric acid, in combination with selective mechanical

removal of incrustations. He implied that differences had developed between the

treatment methods preferred by the Americans and the British when he stated that the

electrolytic process is favored by American workers. Plenderleith also discussed the


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cause of bronze disease, attributing it to electrochemical reactions in the presence of

chloride compounds and moisture, giving rise to light green powdery spots. How to

save a finely patinated bronze when chlorides which exist below the patina have

become activated is one of the major problems in the preservation of metal antiquities,

he wrote.

According to Packard, Plenderleith's book quickly became the Bible for American

conservators (Packard 1993). Also, around this time Joseph Ternbach, who arrived in

New York as a refugee from Europe, was impressing dealers and collectors with

aesthetically pleasing results from his mechanical cleaning treatments on bronzes

(Ternbach 1981). Ternbach spoke about the advantages of mechanical treatment at the

American Association of Museums meeting in Boston in 1948 and published an abstract

of his paper(Ternbach 1949). (For an example of the detail that can be revealed by

careful mechanical cleaning, see figs. 4a, 4b.) These events may help explain why the

Fink method began to fall out of favor.

Fig. 4a. Winged Isis, Egyptian, Late period (663332 B.C.), bronze, 3 in. Collection of the Walters Art

Gallery, acc no. 54.1020. Before mechanical cleaning, 1978.


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Fig. 4b. Winged Isis. After mechanical cleaning by Helen Ganiaris, 1978.

All of the above authors seem to agree about two things: that severely or actively

corroding bronzes should be stabilized and that the aim of treatment should be to restore

the object visually as much as possible to its original state. They showed no interest in

preserving corrosion products for other than aesthetic reasons or for corrosion inhibition

if the patina is thin and adherent. They did not appear to be concerned that the

treatments they recommended change an object's composition by either removing metal

ions or adding metals or their salts to the surface as a byproduct of treatment, e.g.,

redeposited copper with electrolysis and zinc products with electrochemical treatment.

However, some did begin to speak out about the disadvantages of altering the original

metal composition and the advantages of preserving the burial patinas and accretions,

expressing an attitude more in line with that of the professionally trained conservator

today. In a 1935 letter, Earle R. Caley, assistant professor at Princeton University,explained to Robert Garrett, a collector in Baltimore, that he was not currently

interested in the so-called bronze disease but in the chemical composition of bronzes

(Walters Correspondence). He indicated that he had found a correlation between

chemical composition and degree of corrosion and that composition and time of

manufacture are related in certain cases, which enable dating of objects to be done

objectively from chemical analyses. He felt that the study of bronze composition

would have considerable value for detecting modern forgeries of antique bronzes.

Gettens also expressed his interest in what could be learned from the corrosion products

on archaeological bronzes in a letter to Rodney Young of the University of

Pennsylvania Museum on April 9, 1959, just before Young was setting off for Turkey(Walters Correspondence). Gettens sought to enlist Young's help in preventing the loss


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of unusual corrosion products on the bronze objects that were found in the tomb at

Gordion:

I hope you can stay the hands of those who want to clean them off before they can be

examined properly. The variety of copper corrosion products is most astonishing, and I

think merits special study.

Several years later, Hanna Jedrzejewska of the Research Laboratory, Department of

Antiquities, National Museum in Warsaw, supported a change in attitude (Jedrzejewska

1964). She made a case for sampling all elements of a bronze that would become

changed or destroyed in further treatment and suggested that small areas should be left

uncleaned. In another article, she concluded that cleaning is irreversible. A lot of

harm has already been done to the documentary evidence and that uncleaned

artifacts should be considered documents of the past (Jedrzejewska 1976).

Adding to the argument that bronzes and their patinas should be preserved unaltered

were advances in analytical techniques and scientific instrumentation, which made itpossible to learn more from a bronze and its accretions than ever before. This

development encouraged conservators as well as archaeologists to consider more than

just the aesthetic value of the patina and burial deposits. Evidence of other materials

for example, that of textile in contact with bronze during burialcould be studied

through their residues preserved in the bronze corrosion layers, (figs. 5a, 5b).

Fig. 5a. Bowl, Capuan, 6th5th century B.C., bronze, D 13 in. Collection of the Walters Art Gallery,acc. no. 54.144. As received, 1976.

Fig. 5b. Fragment of bowl, Capuan. Evidence of textiles preserved in the corrosion.


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Although the ideal conservation method for arresting bronze disease while preserving

the patina is through control of the environmentfor example, creating low relative

humidity to inhibit corrosionrealistically, such controls cannot be guaranteed for

long-term preservation. A number of treatments have been developed and published in

the conservation literature with the stated goal of stabilizing the bronze artifact while

preserving its patina. Robert Organ, then at the Research Laboratory of the BritishMuseum, introduced the use of silver oxide for treatment of individual spots of bronze

disease (Organ 1961) and reintroduced the use of sodium sesquicarbonate for overall

stabilization (Organ 1963). According to W. A. Oddy and M. J. Hughes of the British

Museum Research Laboratory, bronzes could be stabilized by soaking for prolonged

periods in sodium sesquicarbonate, dissolving the chlorides through the patina (Oddy

and Hughes 1970). The method is simple, effective, and inexpensive; however,

treatment can take over a year to complete, and it was demonstrated that although the

sodium sesquicarbonate dissolved the chlorides, it also dissolved metallic copper

(Weisser 1975).

H. B. Madsen of the Kalundborg Museum in Denmark introduced the use ofbenzotriazole for the treatment of bronze disease without removing the patina

(Madsen 1967). Stabilization could be achieved by soaking a bronze in a dilute solution

of benzotriazole for 24 hours. This technique quickly became the favored method due to

its simplicity and immediate results. With time it became clear that there were bronzes

that could not be stabilized directly with benzotriazole. Such difficult-to-stabilize

bronzes can be treated by applying 5% sodium carbonate solution locally, rinsing

thoroughly to remove all residues before drying, then treating again with benzotriazole

(Weisser 1987). However, this treatment is not always successful or appropriate for all

bronzes. Work still must be done to develop reliable methods to stabilize actively

corroding bronzes without adversely affecting the core of remaining metal and without

altering the patina and burial accretions.

3 CONCLUSIONS

From the perspective of the archival materials and publications in the holdings of the

Walters Art Gallery, it can be demonstrated that there has been a major change in the

approach to the treatment of severely or actively corroding bronzes in the United States.

Rather than striving to return an object visually to its original form, there is an emphasis

on learning all that one can from the artifact, from its patina, and from its preservedaccretions. The conservator and archaeologist today must hesitate to remove soil or

corrosion present on an object since such treatment may affect the ability to discover

information about the object and its original and burial contexts. If adopted, the

proposed revision of the American Institute for Conservation Code of Ethics and

Guidelines for Practice would formalize the conservator's responsibilities to scientific

research by requiring the conservator to take into account the effects of materials and

methods on future examination and analysis. Since the conservator also has a

responsibility to preserve the artifacts, and no permanent, safe, and reliable treatment

for bronze disease has yet been developed, further collaboration is needed between

conservators and scientists to satisfy this need.


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ACKNOWLEDGEMENTS

The author would like to thank Donna Strahan and Julie Lauffenburger, her colleagues

at the Walters Art Gallery, who made many useful suggestions for improving this paper.

This paper is dedicated to the late Elisabeth Packard, whose insistence on scrupulous

documentation and preservation of records during her many years at the Walters ArtGallery made this historical review possible.

NOTES

1. Alfred Andr was a Parisian restorer who early in this century treated many objects in

the Walters collections and other American collections.

NOTES

2. Nichols had warned in his book that insufficient washing after the electrolytic

treatment would cause efflorescences of carbonate of soda to form from the retention of

residues of the electrolyte in the pores of the bronze.

REFERENCES

Fink, C., and C. H.Eldridge.1923. Efficient method for restoration of antique bronzes

badly corroded or crusted over. Unpublished typescript. Walters Art Gallery.

Fink, C., and C. H.Eldridge.1925. The restoration of ancient bronzes and other alloys.

New York: Metropolitan Museum of Art.

Finkener, A.1905. Electrolytic treatment method described in F. Rathgen, The

preservation of antiquities. Cambridge, Eng.: Cambridge University Press.

Frisch, C.1904. Natural patina and artificial patina.Revue de Chimie

Industrielle15:16974.

Garland, H., and C. O.Bannister. 1927.Ancient Egyptian metallurgy. London: Charles

Griffen and Co.

Jedrzejewska, H.1964. The conservation of ancient bronzes. Studies in

Conservation9:2330.

Jedrzejewska, H.1976. A corroded Egyptian bronze: Cleaning and discoveries. Studies

in Conservation21:10114.


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Laufer, B.1930. Foreword toRestoration of ancient bronzes and cure of malignant

patina, by H. W.Nichols.Chicago: Field Museum of Natural History.

Lucas, A.1932.Antiques: Their restoration and preservation. London: Edward Arnold

and Co.

Madsen, H. B.1967. A preliminary note on the use of BTA for stabilizing bronze

objects. Studies in Conservation12:16367.

Nichols, H. W.1930.Restoration of ancient bronzes and cure of malignant patina.

Chicago: Field Museum of Natural History.

Oddy, W. A., and M. J.Hughes. 1970. The stabilization of active bronze and iron

antiquities by the use of sodium sesquicarbonate. Studies in Conservation15:18389.

Organ, R.1961. A new treatment for bronze disease.Museums Journal61:5456.

Organ, R.1963. The examination and treatment of bronze antiquities. InRecent

advances in conservation, ed.G.Thomson. London: Butterworths. 10410.

Packard, E.1993. Personal communication. Formerly Walters Art Gallery.

Plenderleith, H. J.1934. The preservation of antiquities. London: Museums Association.

Plenderleith, H. J.1956. The conservation of antiquities and works of art. London:

Oxford University Press.

Rathgen, F.1905. The preservation of antiquities. Cambridge, Eng.: Cambridge

University Press.

Robinson, E.1925. Introduction to The restoration of ancient bronzes and other alloys,

by C.Fink and C. H.Eldridge.New York: Metropolitan Museum of Art.

Rocchi, F.1920. Contribution of the experimental sciences in art and history.Rassegna

d'Arte7:25864.

Scott, A.1921. The cleaning and restoration of museum exhibits (report upon

investigation conducted at the British Museum, Department of Scientific and IndustrialResearch). London: H. M. Stationery Office.

Scott, A.1923. The cleaning and restoration of museum exhibits, 2d report. British

Museum, Department of Scientific and Industrial Research. London: H. M. Stationery

Office.

Ternbach, J.1949. Restoration of ancient bronzes.Museum News26 (17):78.

Ternbach, J.1981. Oral history interview by S. Weintraub. Steven Weintraub, Art

Preservation Services, New York, N.Y. To be filed with FAIC Oral History Project.


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Walters Correspondence. Archives, Walters Art Gallery Conservation Laboratory,

Baltimore, Maryland.

Weisser, T.1975. The de-alloying of copper alloys. In Conservation in archaeology and

the applied arts. London: International Institute for Conservation of Historic and

Artistic Works. 20714.

Weisser, T.1987. The use of sodium carbonate as a pre-treatment for difficult-to-

stabilize bronzes. InRecent advances in the conservation and analysis of artifacts.

London: Summer Schools Press. 1058.

AUTHOR INFORMATION

TERRY DRAYMAN-WEISSER has been director of conservation and technical

research at the Walters Art Gallery since 1977. She has a B.A. in art history from

Swarthmore College and received a diploma with distinction from the University of

London, Institute of Archaeology in the conservation of archaeological materials in

1973. The subject of her thesis was the dealloying of bronze and brass. In addition, she

studied metallurgy in the graduate program at Johns Hopkins University. She has

worked as site conservator on several archaeological excavations and has lectured and

published widely on the deterioration and preservation of metal objects. Address:

Walters Art Gallery, 600 N. Charles St., Baltimore, MD 21201.

Drayman, T. a Perspective History Conservation Archaeoloical Cooper. 1994

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Transcript of Drayman, T. a Perspective History Conservation Archaeoloical Cooper. 1994