Mercury Gilding in Today's Japan: an Amalgam of Old And

ISIJ International, Vol. 54 (2014), No. 5, pp. 1106–1110

Mercury Gilding in Today’s Japan: An Amalgam of Old and New

Alessandra GIUMLIA-MAIR,1)* Yasunosuke MORIMOTO IV2) and Ken’ichi OTA3)

1) AGM Archeoanalisi, via E. Toti 8, I – 39012 Merano (BZ), Italy. 2) Morimoto Kazari Kanagu Seisakujo, 59 Yaoyacho, Yobaidori Nishinotoin Higashiiru, Shimogyoku, Kyoto, 600-8321 Japan. 3) Q Inverse Inc., 2-14-303, Mino 7, Mino, Osaka, 562-0001 Japan. (Received on November 30, 2013; accepted on March 3, 2014)

Mercury gilding (amalgam gilding or fire gilding) is an ancient technique, and it is apparently attested in the West from around the mid first millennium BC. We must note, however, that only very few gilt objects have been properly analysed and that, until now, the problem of the origin of mercury gilding is generally very little researched in different parts of the world. The earliest examples of amalgam gilding in Asia seem to come from China and are dated to the Chan Kuo or Warring States period (475–221 BC). It is unknown exactly when the earliest amalgam gilt objects appear in Japan. This technique, however, seems to have been used surely since the Nara period (710–794 AD), and it was widely employed in the Edo period. In recent times, this technique has disappeared from all decorative metal workshops, with very few exceptions, because of the high toxicity of mercury. A notable exception is the Morimoto Kazari Kanagu Seisakujo in Kyoto, a specialized workshop that is very active in the restoration and reproduction of decorative metal details in the field of Cultural Heritage. The workshop has operated since 1877 (Meiji period) by using ancient techniques, including amalgam gilding, to produce architectural metal fittings, metal dec- orations of shrines and ceremonial utensils. In this paper, the beginnings of the technique will be briefly outlined, and the procedures employed in the Morimoto workshop for the production of traditional decorative metalwork will be described and discussed.

KEY WORDS: mercury gilding; Japan; Jofuku; cinnabar.

Mercury boils at 357°C, and cinnabar, burnt in the pres- 1. Introduction ence of oxygen, breaks down and releases mercury vapour Mercury gilding—also known as amalgam gilding or fire at 600–700°C. Metals with a low melting and boiling tem- gilding—is an ancient technique, and it is attested in the perature—such as mercury, arsenic and zinc—when smelted West from around the mid first millennium BC. For the in a common furnace, will decompose and disappear as moment, however, only very few gilt objects have been vapours up the chimney. One way to recover and use them properly analysed; the problem of the origins of mercury is to employ the mineral as it is and produce an alloy by gilding, therefore, is very little researched in most parts of cementation with another metal. This would be done in a the world. crucible covered with charcoal to avoid oxidation as much For a long time, the earliest example of amalgam gilding as possible. The process already may have been known in in the West was considered to be a gilt fitting1,2) found in the Bronze Age and employed with copper and arsenic to excavations in Rathgall, Ireland, dated to the 6th century BC produce arsenical copper. It was certainly used in Roman (i.e., to the local Late Bronze Age). Another gilt object from times, with copper and zinc to produce brass.12,13) A second the same context, however, does not contain mercury, like possibility to avoid the decomposition and volatilisation in the other analysed finds belonging to this period;3,4) its date air of metals with a low melting and boiling temperature is therefore has been recently challenged.5) the distillation of the mineral, as was done in the case of Fire gilt objects dated to a couple of centuries later—to mercury. the Iron Age and Hellenistic times—are known from other parts of Europe. Some Greek and Iberian objects have been 2. The History of Mercury identified,6–9) but the well known and widely quoted Bronze Age sword hilt from North Rhine Westphalia10) now seems 2.1. The Distillation of Cinnabar in European Prehis- to be modern,11) and not much is known from other areas. tory and Classical Antiquity The use of this technique must obviously be connected Ancient distillation processes are known from as early as with the availability of mercury and/or with the know-how the 4th–3rd millennium BC. A well-known early distillation necessary for the distillation of cinnabar. vessel found in Mesopotamia was most probably used for * Corresponding author: E-mail: [email protected] distilling herbs, gums and oils in the production of per- 14,15) 16) DOI: http://dx.doi.org/10.2355/isijinternational.54.1106 fumes, as described in later cuneiform texts. Several

© 2014 ISIJ 1106 ISIJ International, Vol. 54 (2014), No. 5 classical texts mention distillation.17) The most detailed mass. When they are weighed, four sextarii of mercury come examples come from the Alexandrian alchemists, and they to 100 librae…. Mercury, moreover, is useful in many also contain various illustrations of aludels (i.e., condensers) instances. For neither silver nor brass can be properly gilt and alembics (i.e., stills).18) Some of the classical texts even without it. And when gold is embroidered in clothing and the describe the distillation of cinnabar. garment, worn out with old age, has no decent use, the cloth The earliest description known—at least until now—of is put into a clay vessel and burnt over the fire. The ash is the distillation of cinnabar is in the Materia Medica (περι thrown into water and mercury is added to it. The mercury υλης ιατρικης), written in the 1st c. AD by Pedanius then gathers all the particles of gold onto itself and com- Dioscorides, a Cilician-Greek born in Anazarbos in Asia bines with them. Once the water is poured off, the remainder Minor, who was a physician, pharmacologist and botanist.19) is spread over a cloth and pressed by hand. The mercury, He states: “Putting an iron bowl containing cinnabar in a since it is liquid, passes through the texture of the cloth clay vessel, they cover it with a helmet (-shaped vessel) when forced by the pressure, and pure gold is found in the smearing it with clay, then they heat it with coals; the soot cloth” (transl. Humphrey et al.).21) which adheres to the vessel, becomes mercury when scraped There is one caveat, in this text Vitruvius is calling cinna- off and cooled ” (transl. Giumlia-Mair). bar “minium” (i.e., lead oxide) instead of vermilion (mercury Pliny, the famous Roman encyclopedist of the 1st century sulphide), but the process he describes refers to cinnabar. AD, describes this process with almost the same words and adds: “the cleaned condensed liquid which becomes the 2.2. Early Mercury Mines in Europe colour of silver and (has) the fluidity of water, ... is also The earliest known cinnabar mine in Europe is that of divided into drops and runs down like a slippery liquid ”. 20) Šuplia Stena, on Mount Avala in Serbia. The cinnabar was Pliny is also the first author who makes a distinction already dug out of that mine in the Eneolithic. The local between argentum vivum, (i.e., native mercury) and hydrar- Kostolač Culture employed it as the bright red pigment ver- gyrum (i.e., mercury obtained by distillation from cinnabar). milion.22) At the famous site of Vinča, approx. 20 km away A further famous text describing the extraction of mercu- from Šuplia Stena, several furnaces have been found during ry is that written by Vitruvius, the illustrious Roman archi- an excavation. Both Miloje Vasič and Alexander Durman tect: “Now I will proceed to explain the treatment of minium hypothesized that these structures had been employed for (here vermilion or sulphide of mercury) The material, which smelting the cinnabar of the mine.23,24) is called ore, is dug up, then they produce minium by treat- After Dioscorides,19) cinnabar was extremely expensive ing it. In the veins the ore is like iron, more ruddy in colour, and came from Libya. The most important mercury mines and having reddish dust around it. When it is dug up and in antiquity were the Cilbian Fields of Ephesus, in western beaten with iron tools, it exudes many drops of mercury, Anatolia and the famous Almaden mines in Spain, but there which are collected quickly by the miners. Once this ore has was also cinnabar of lesser quality in Colchis, Carmania and been collected in the workshop it is placed in a furnace to Ethiopia.25) From Vitruvius,21) we know that the Spanish cin- dry because of its large amount of moisture. Next, when the nabar was brought to Rome and dealt with by the publicani in steam stirred up by the heat of the fire condenses on the the workshops between the temples of Flora and Quirinus. floor of the furnace, it is discovered to be mercury. After the ore is taken away, the drops which remain because they are 2.3. Gilding in Classical Antiquity too small to be collected are swept together into a container Fire gilding, amalgam gilding and mercury gilding are of water where they run together and are combined into one different names indicating the same technique that, in the

Fig. 1. Pattern for gilt decoration by Morimoto Kazari (Photo A. Giumlia-Mair).

Fig. 2. Mercury and gold amalgam at Morimoto Kayari (Photo A. Giumlia-Mair).

West, was perhaps invented in the Hellenistic period, but it lute has dried bury the lower jar in the ground so that the became common only in Roman times. This was neither the rim appears about an inch above the earth. Then build a only nor the oldest technique known in antiquity. After plat- stove surrounding the upper jar so that fire can be applied ing with a thicker gold sheet, foil gilding seems to have been all about it to heat the contents. Let four openings be made, the earliest technique on metals. The foil was applied direct- one on each side of the stove, to supply air for the burning. ly on the surface and simply burnished with hard polished After heating for two hours the mercury will trickle down stones such as agate or hematite. On non-metallic materials into the lower jar.”28) (e.g., wood, leather and ceramics), the gold foil was attached A second description of the process, mentioned by on the objects by using organic glues such as apple juice, Needham,28) is in the book Ling Wai Tai Ta (Information on fish glue, milk, garlic juice, egg white or blood. What is Beyond the Passes), dated 1178 AD. It states: “The A less well-known technique, described in the Leyden people of Yung turn cinnabar into mercury as follows. Iron papyrus,26) was gilding with lead. This method involved is used to make an upper and a lower bowl-like vessel. The mixing one part of gold filings with two parts of lead filings. upper vessel holds the cinnabar, which is separated by an The mixture was applied with an organic glue to the surface iron plate with small perforations. The lower vessel contains of the pieces to be gilded and strongly heated to oxidize the water and is buried in the ground. The two are joined mouth lead and induce its evaporation.27) to mouth and sealed together just at ground level. A strong Mercury gilding (Fig. 2) was obtained by mixing gold fil- fire is then applied. On being heated the cinnabar changes ings with mercury to obtain an amalgam that was then applied into vapour, and on coming into contact with water it con- on copper-based objects containing very low amounts of tin denses, descending thus in the form of mercury.” and/or zinc and mostly no lead. The objects were then heated, By this time the process was quite advanced. The earliest and the mercury evaporated leaving a porous gold layer. The examples of amalgam gilding in Asia come from China,29,30) last stage was the burnishing of the gilt surface.27) and are dated to the Chan Kuo or Warring States period (475–221 BC). We do not know when exactly the earliest amalgam gilt objects are to be found in Japan, however; this 3. Mercury in Asia must have happened at a time in which both mercury and 3.1. Distillation of Mercury and Early Amalgam Gild- gold were available. ing in China and Japan Several Chinese texts, dated to the last centuries of the 1st 3.2. Jofuku millennium AD, discuss the distillation of mercury and The story of the Chinese “magician” Hsu Shi, who was describe in detail the apparatus.15) The Sung text Pen Chao sent by the Chin Emperor Shi Huang Ti (259–210 BC) from Tu Ching, dated 1062 AD, recommends: “Take a jar made China to Japan to the “three supernatural islands” in which at Yang Cheng and fill it with cinnabar mixed with small “the immortals and the drug which prevents death can be pieces of hard charcoal. Cover the mouth of the jar with a found”, seems to be connected with both mercury and piece of iron sheet that has been perforated with small gold.31,32) Hsu Shi prepared an expedition and went by holes. Hold the iron sheet in position by fixing a length of ship—together with 3 000 young men and women and many iron wire around the jar. Then invert the jar and place it labourers—to the Japanese islands (the three sacred islands over another similar jar containing water in such a way that in the midst of the sea) on the quest for the wonderful drug the two come into contact mouth to mouth. Apply a lute com- that, as in all Chinese alchemistic recipes, must have con- posed of salt, clay and pig’s hair all over the upper jar, and tained mercury and gold, but he never went back to the especially round the rim where the two jars meet. After the emperor. The grave of the alchemist Hsu Shi, known in

Japan as Jofuku or Joshi, is still venerated as that of a sage employed in Japan from early times and until the Meiji period and wise man by the locals who pray there for longevity and (1868–1912). In the rich Japanese cultural heritage, innumer- happiness. The grave is located in the city of Shingu on the able examples of amalgam gilding exist, particularly in tem- main island of Japan, at the easternmost point of the ples, and they need care and skillful hands for restoration. Wakayama Prefecture, at the estuary of the Kumano River, and it is one of the places of interest in the Yoshino-Kumano 4. Mercury Gilding in Today’s Japan National Park. The story of the alchemist Hsu Shi is also reported in the Chinese book Shi Chi (Historical Memoirs) 4.1. Mercury Gilding in Modern Times in Japan by Su Ma Tan and Su Ma Chien (2nd–1st century BC), so The employment of mercury in industry and for other it is quite clear that at this time alchemists were also active applications has greatly diminished in the last decades, in Japan. At the latest in the time of Hsu Shi amalgam gild- together with the increase of health and safety regulations. ing, which was was already used in China, must have been In the European Union, for example, trade and industrial known in Japan, too. employment of mercury have been banned from the entire This technique therefore seems to have been widely Union territory since 2011 because of its high toxicity.

Fig. 3. One of the braziers used by Morimoto Kazari (Photo A. Giumlia-Mair).

Fig. 4. Partially gilt plate (Photo K. Ota).

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