# The story of the “Qiulai” qin unraveled by radiocarbon dating, Chinese inscriptions and material characterization

Marie-Gabrielle Durier, Alexandre Girard-Muscagorry, Christine Hatté, Tiphaine Fabris, Cyrille Foasso, Witold Nowik, Stéphane Vaiedelich

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Marie-Gabrielle Durier, Alexandre Girard-Muscagorry, Christine Hatté, Tiphaine Fabris, Cyrille Foasso, et al.. The story of the “Qiulai” qin unraveled by radiocarbon dating, Chinese inscriptions and material characterization. Heritage Science, 2021, 9 (1), pp.89. 10.1186/s40494-021-00563-8. hal-03300370

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# The story of the “Qiulai” *qin* unraveled by radiocarbon dating, Chinese inscriptions and material characterization

Marie-Gabrielle Durier<fnref n="1" />,²,³*, Alexandre Girard-Muscagorry³,⁴, Christine Hatté<fnref n="1" />*, Tiphaine Fabris²,⁵, Cyrille Foasso⁶, Witold Nowik²,⁵ and Stéphane Vaiedelich²,³

**Abstract**

An ancient table zither *qin*, an emblematic stringed instrument of traditional Chinese music, has been rediscovered in the museum collection of the Conservatoire National des Arts et Métiers (inv.4224, CNAM collection), Paris. This instrument named "Qiulai" *qin*, whose origin is poorly documented, can claim to be one of the oldest *qin* preserved in European collections; its state of conservation is exceptional. A thorough examination was carried out based on an innovative approach combining museum expertise, material characterization analyses (optical microscopy, VIS/IR/UV imaging, X-ray fluorescence, SEM-EDS, Raman) and advanced radiocarbon dating technology (MICADAS). Our results highlight the great coherence with the traditional manufacturing practices mentioned in early Qing dynasty *qin* treatises and poems, in particular the collection of materials with highly symbolic meanings referring to the *qin* sound, nature and the universe. The reuse of resinous wood of the *Taxus* family from a building such as a temple has been demonstrated. The ash layer contains bone black, crushed malachite and residues of silica, ochres, potassium and magnesium aluminosilicates. Our study confirms the antiquity of the "Qiulai" *qin* in Europe by indicating that it was most likely made in the small [1659–1699] interval of about 30 years at the turn of the eighteenth century.

**Keywords:** *qin*, Chinese zither, *Tang Kai*, Musical instrument, eighteenth century, Radiocarbon dating, Spectroscopy, Qin dynasty texts

**Introduction and research aims**

The *qin* or *guqin* (“old *qin*”) is a seven-stringed Chinese table zither regarded as one of the oldest chordophones in China. Based on surviving early written sources and archeological findings, the instrument is attested since the Zhou dynasty (eleventh-fifth century B.C.) and its definitive organological features were established during the Western Jin dynasty (265–316) [1]. Its construction appears simple but allows a wide variety of sounds, from deep bass to crystal-clear high-pitched notes, and

finger strokes that can be or gentle or violent. This highly esteemed and mainly solo instrument connotes the refinement and sophistication of the literati, the Chinese scholarly elite, along with the practice of poetry, painting, calligraphy and chess [2]. The *qin* is considered as one the objects that best epitomizes Chinese thought [1].

Beyond the elaborate sound images it produces, the *qin* is also revered as a refined artwork, whose shape is imbued with a strong symbolic meaning. The different parts of the instrument refer to the dragon, the phoenix, the sky and the earth. The making of a *qin* corresponds to an ideal such as a concentration of the harmony of nature, the energetic flow (*qi*), and all the forces of the Universe [1]. The materials selected are therefore invested with deep meaning, such as timber from temples that is impregnated with chanting, or from trees growing near

<footnote>*Correspondence: marie-gabrielle.durier@lsce.ipsl.fr; christine.hatte@lsce.ipsl.fr</footnote>

<footnote n="1">¹ Laboratoire des Sciences du Climat et de L'Environnement, UMR 8212
CEA CNRS UVSQ, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
Full list of author information is available at the end of the article</footnote>
water cascades, or in calm and secluded places, etc. Great value is attributed to the numerous cracks (duanwen) on the surface lacquer layer which are considered as a sign of "antiquity", one of the virtues embodied by the *qin* [3, 4].

The ten-year Cultural Revolution (1966–1976) in China had important consequences on the arts, including on the teaching and practice of *qin* and listening to this instrument [5]. Like other symbols strongly associated with the elites of the Old Empire, efforts were made to "target for destruction" multi-century *qin* [6]. Nowadays, modern *qin* makers, recognized as the heirs of this ancestral tradition, perform their work with the remaining knowledge that survived the cultural compliance policy under Mao Zedong [7]. Considering its long history, its numerous cultural and symbolic associations and its crucial role in the shaping of Chinese culture, the *qin*—along with its musical repertoire—was included in 2008 in the UNE SCO list of Intangible Cultural Heritage of Humanity.

To our knowledge, the *qin* rediscovered in 2012 in the collections of the Conservatoire National des Arts et Métiers (CNAM, Paris) is the oldest *qin* known in European museum collections.<fnref n="1" /> In view of the evidence in favour of its authenticity, its value is considerable. Research combining a series of scientific techniques and early written sources remains relatively inaccessible and can only be found in Chinese scientific literature or well-informed Chinese expert circles [8]. Likewise, while the literature on Chinese lacquers is abundant [9–12], few scientific reports are available on the material characterization of early *qin* lacquers [8, 13]. However, information related to the making of *qin* appears in the numerous poems praising the instrument and in ancient treatises that shed light on the origin and use of materials [14].

This article combines visual examination of the instru-
ment by *qin* experts, material characterization analyses
and advanced radiocarbon dating technology in an inter-
disciplinary framework. We will demonstrate that the
scientific investigations on the different parts of the *qin*
from the CNAM collection are consistent with the prac-
tices of *qin* craftsmanship that follow a steady tradition
throughout the Qin dynasty, as depicted in the follow-
ing seventeenth and eighteenth-century written sources:
the *Qinfang* "Twenty Four Flavours of *qin***" which is an
early treatise written c.1641 by Xu Shangying [4] and the
*Yuguzhai Qinpu* "Abiding with Antiquity" written c.1860
by Zhu Fengjie which is a very popular late Qing dynasty
*quqin* handbook [3].

Description of the “Qiulai” qin

An exceptional Chinese zither in European collections

The *qin* under study is a Chinese table zither owned by
the Conservatoire National des Arts et Métiers (CNAM,
inv. n° 04,224) and currently on loan to the Musée de la
musique since 2015 (inv. n° D.04224) (Fig. 1). This *qin*

is composed of a soundboard apparently made from a
single block of wood, without a bottom, with a system
of bridges, peg pool, a nut, two feet to attach seven silk
strings, respectively on and under the forehead, the end
(tail) and below the soundboard of the *qin* [15]. Thirteen
round studs or emblems (*hui*) of mother-of-pearl are
aligned to mark harmonic positions. The upper and lower
parts of the *qin* symbolize the sky and the earth; two pil-
lars under the soundboard in a circular and a crescent
moon shape are called respectively the pillars of “Heaven”
and “Earth” (Fig. 1). Visually, the front side is black and
the back side is reddish.

<figure><img src="image_4.png" /><figcaption>**Fig. 1** The Chinese zither or *qin* from the CNAM collection (inv. n°04224) (dimensions: 1322 x 237 x 65 mm). *The silk strings were strung in 2018 at the Musée de la musique, Paris.* Pictures of the front and back sides of the *qin*, and the zoom in of Tang Kai's seal taken by *Claude Germain* © Musée de la musique, Cité de la musique—Philharmonie de Paris. https://collectionsdumusee.philharmoniedeparis.fr/doc/MUSEE/1105337/cithare-qin</figcaption></figure>

<footnote n="1">¹ The MET, New York, keeps a *qin* that belonged to Prince Lu and dated from 1644.
https://www.metmuseum.org/art/collection/search/503523.</footnote>
This *qin* was rediscovered in 2012 during the “récolement”<fnref n="2" /> of the musical instruments of the CNAM acoustic collection. Philippe Bruguière, the former Curator of non-European collections at the Musée de la Musique, suspected its old age. The Musical Instrument Museums Online database (MIMO)<fnref n="3" /> was queried to compare this instrument with other *qin* listed in partner museums, as well as for *qin* from private collections [16]. The *qin* has exceptionally rare features with a leaf banana shape known as *jiaoye 焦葉* style and the absence of a bottom. The shape and the carved date situate its manufacturing period during the 17th or eighteenth century in China. For comparison, the “Gumeihua” *qin* with a similar shape in China (Forbidden City) was made during the Ming 明 dynasty (1368–1644) and once belonged to the collection of the Emperor Qianlong 乾隆 (1735–1796) [17]. The rediscovered *qin* is assumed to be one of the oldest *qin* kept in European museum collections.

Despite previous studies based on the CNAM archives and inventories, its provenance remains mysterious. The CNAM was created in 1794 following decrees issued during the French Revolution to promote national industry. The researchers of the CNAM gathered the following clues [18]:

* The presence of musical instruments is attested since 1814 at the CNAM with the installation of the early "Cabinet de physique de M. Charles" who was elected as a physicist to the Académie des Sciences in 1785 [19].

* The *qin* n°4224 is clearly mentioned in the inventories edited in 1849 at the Conservatoire<fnref n="4" /> for the creation of the acoustics gallery in 1851–1852.

* Objects with inventory numbers around 4000 were presumably kept at the Académie des Sciences prior to their transfer to the Conservatoire.<fnref n="5" /> The Académie des Sciences was initially created in 1666 as an informal scholarly circle and kept collections of objects for scientific studies and education. Some objects were taken from these collections to complete the collection of the Conservatoire after the French Revolution.

## Inscriptions and meaning

The inscriptions engraved on the back side of the *qin* are reported in Fig. 2. First, they refer to the name of the instrument “Qiulai” 秋籟 meaning "Autumnal resonances" (Fig. 2a). The following inscriptions in carved Manchu reproduce an extract from the famous poem "Qinzan" 琴贊 "In praise of the *qin*" written by Li Bai 李白 (701–762) (except the first verse and some slight modifications in red (Fig. 2b). The bottom part of the inscriptions includes information on the making of the instrument (Fig. 2c) and Tang Kai's seal (Fig. 2d). Tang Kai 唐凱 was a well-known court zither player and zither maker, as well as a *qin* collector during the reigns of the Chinese emperors Yonzheng 雍正 (1722–1735) and Qianlong 乾隆 (1735–1796) of the Qing 清 Dynasty (1636–1912) [17]. The inscription Songtao 松濤 "gusts of wind in the pines" refers to the nickname of Tang Kai whose complete *hao* (i.e. pseudonym) is Longwan cunsou Songtao 龍灣村叟松濤 "the so-called old man of the gusting wind in the pines of Longwan".<fnref n="6" /> According to the carved inscriptions (Fig. 2c), the making of the *qin* is dated 1712, which is consistent with the period of activity of Tang Kai. This maker is known to have owned seven ancient *qin* 古琴 with similar inscriptions and the same seal as the "Qiulai" *qin* [20]. However, no early written sources mentioned this "Qiulai" 秋籟 *qin* in his collection, even though the name is common for a musical instrument.

## Material composition

### Wood

The monoxylous wooden body of the "Qiulai" *qin* is made of the light porous brown resinous species from the *Taxus* genus belonging to the *Taxaceae* family.<fnref n="7" /> The forehead of the *qin* has been carved in hardwood teak, i.e. *Tectona grandis* from the *Lamiaceae* family.

Based on the legacy of the surviving written sources and the practices of modern makers, the commonly mentioned wood species for each part of the instrument are as follows [14]<fnref n="8" />:

i. For the soundboard: *tong* 桐 tree, *wutong* 梧桐, *paotong* 泡桐, *qingtong* 青桐, etc.; or spruce 雲杉, or cedar *shan* 杉 or "cloud fir wood" *yunshan* 雲杉.

<footnote n="2">² An operation to check the presence of documents and objects in the collections of French national museums updated every ten years.</footnote>

<footnote n="3">³ MIMO: Musical Instrument Museums Online—http://www.mimo-inter.national.com/MIMO/ (accessed: 21/05/03).</footnote>

<footnote n="4">⁴ A figure of the *qin* is also briefly presented in the official catalog of the Conservatoire collections from 1905: ""King" (Fig. 12 no. 4224) Chinese stringed instrument". The term "Conservatoire" is used here to avoid anachronisms due to the numerous changes of name of the CNAM over time.</footnote>

<footnote n="5">⁵ The objects with inventory numbers from 3570 to 4541 do not have a well-documented provenance. They likely came from the Académie des sciences in Paris, but they may also have come from property seized by revolutionaries from nobles who fled France during the French Revolution, or from lootings during Napoleon's conquests across Europe.</footnote>

<footnote n="6">⁶ Personal communication from François Picard (2013/12/17).</footnote>

<footnote n="7">⁷ Botanical identifications performed by Victoria Asensi (©Xylodata), 2015/01/14, and by Catherine Gill (Laboratoire de Paléobotanique, Université Pierre et Marie Curie, Paris), 2015/04/14, based on micrographs taken by Anne Houssay with an optical microscope Zeiss Axio Scope.A1 Vario and by comparing to a database of Chinese forests (http://www2.affrc.go.jp/fdb/esawoodq/wood.html). Reports available at the Musée de la musique.</footnote>

<footnote n="8">⁸ Wood species listed in a personal communication from Lucie Rault (2021/03/29).</footnote>
<table><thead><tr><th>Original inscriptions</th><th>Translations</th></tr></thead><tbody><tr><td>a 秋籟。</td><td>Autumnal resonances¹</td></tr><tr><td>b 峴阳孤桐,石耸天骨。<br>盛京赤柏</td><td>Upon the craggy slopes near the peak, <u>the solitary tong tree</u>²<br><span style="color:red;">crimson cypress of Shengjing</span><br>Hoists itself upon the rock like some celestial skeleton</td></tr><tr><td>根老冰泉,叶苦霜月。<br>枝茂</td><td>Its venerable roots appear as streams stilled by frost<br>And <u>its fragile leaves</u> as though iced by the moon<br><span style="color:red;">its lush branches</span></td></tr><tr><td>斫为绿绮,徽声粲发。<br>徽音</td><td>Its wood is carved to produce the most exquisite instrument,<br>Whence <u>the notes</u> exuding from its emblems³ sparkle as they spread,<br><span style="color:red;">delicate sounds</span></td></tr><tr><td>秋风入松,万古奇绝。<br>清</td><td>Resonating like the autumn wind that passes through the pines:<br><u>A wonder</u> that will remain forever unequaled!<br><span style="color:red;">crystal-clear</span></td></tr><tr><td>c 大清康熙五十一年歲次,<br>壬辰春龍灣村叟松濤 砍</td><td>51st year of the Kangxi era of the great Qing⁴<br>The old man Songtao carved the instrument in the village of Longwan<br>in spring 1712⁵</td></tr><tr><td>橫琴山廬藏</td><td>Hoarded in the hermitage of Hengqinshan («horizontal qin mountain»)</td></tr><tr><td>d</td><td>Tang Kai's seal</td></tr></tbody></table>

**Fig. 2** The inscriptions carved on the back side of the *qin* and their meaning: **a** the name of the *qin*: ¹lai籟 is a polycalamus flute of the *yue* 俞 type with three holes. The *qin* tends to reproduce the soft and nostalgic sounds of this "antique" flute suggesting an autumnal atmosphere. **b** "In praise of the *qin*", Li Bai's poem (translation by Lucie Rault): the original text is in black, the modified passages carved in the *qin* are in red and under the corresponding sonograms. ² *tong* 桐 (in original version) or *wutong* 梧桐 [21]. ³ *hui* 徽 studs that mark harmonic positions, **c** information on the making of the *qin*: ⁴ dated from 1712 according to the era mentioned under the Qing Dynasty, ⁵ dated from the spring of the year *renchen* 壬辰, which is the name of the sexagesimal year corresponding to 1712 (according to the cyclic calendar), **d** Tang Kai's seal

ii. For the back side: *zi* 梓 or *qiu* 津 trees, i.e. catalpa; or *qi* 漆 tree i.e. *Toxicodendron vernicifluum* or lacquer tree.

iii. For the foot: *wu* 烏 tree, i.e. black ebony.

The *Taxus* wood is not a conventional wood used in the making of *qin* since the Chinese literature and tradition mainly cite the *tong* 桐 tree as the foremost wood used [3, 14, 22].

**Coating**

The wooden body of the "Qiulai" *qin* is completely covered with black and red coatings, providing a strong impression of the homogeneity and cohesion sought by the *qin* maker [4]. We will choose the term "lacquer" in the following due to the traditional use of raw tree lacquer as organic binder (Additional file 1: Fig. S1). Traditionally, the lacquer ash layer *huitai* 灰胎 is applied on the wood support as the preparation layer. It is usually
<figure><img src="image_5.png" /><figcaption>**Fig. 3** Location of the samples on the *qin*: a schematic view of the *qin* and location of the five samples, b pictures of the sampling location by Stéphane Vaiedelich © Musée de la musique, Cité de la musique—Philharmonie de Paris</figcaption></figure>

described as a miscellaneous mixture of *Toxicodendron vernicifluum* lacquer, deer bone powder, deer antler, pig's blood, brick, lime, mother-of-pearl, gypsum, gold, silver, jade, agate, coral, shells, etc. The lacquer was applied in several layers to give the finishing veneer. Great value is attributed to ancient *qin* whose lacquer layer is marked by numerous cracks named *duanwen* 斷紋. Surprisingly, the lacquered surface of the "Qiulai" *qin* has no cracks (*duanwen*).

## Silk

The strings that were found knotted around the feet and the bridge prior to their changes in 2018 are made of silk (Fig. 3). The silk came traditionally from insect cocoons

named *jiacan* or domestic silkworm in Chinese and the species used is Bombyx mori. A coating of dirt, glue or wax on the surface of the strings is visible, ranging from off-white to brown-black. Early recipes suggest the use of fish glue, wax or boiled rice for the impregnation of boiled silk strings that helps hold the fibers together and influences the sound [3].

## Methods

### Sampling

Micro-sampling was performed on the *qin* for radio-carbon dating. The size of the samples ranged from 0.2 to 1.4 mg on discrete parts of the back of the body of the *qin* in order to respect the aesthetic integrity of the object (Fig. 3, Table 1).
<table><caption>**Table 1.** Description of samples Q1 to Q5.</caption><thead><tr><td>Sample</td><td>Location</td><td>Material composition</td></tr></thead><tbody><tr><td>Q1</td><td>Bottom of the foot pool</td><td>Wood</td></tr><tr><td>Q2</td><td>Pillar – back of the qin</td><td>Wood</td></tr><tr><td>Q3</td><td>Foot</td><td>Wood</td></tr><tr><td>Q4</td><td>String</td><td>Silk</td></tr><tr><td>Q5</td><td>Coating crack near the foot pool</td><td>Coating stratigraphy</td></tr></tbody></table>

## Material characterization analyses

### Optical and digital microscopy

First, the stratigraphy of the lacquers was observed in-situ under visible (VIS), infrared (IR) and ultraviolet (UV) rays using VIS/IR/UV imaging on a Dino-Lite with DinoCapture 2.0 software. Then, a chip of the coating, which comprises the complete stratigraphy from the surface to the wood support, was investigated using light microscopy (Zeiss Axio Scope.A1 Vario) and digital microscopy (3D Keyence-VHX).

### X-ray fluorescence

A preliminary investigation was done using X-ray fluorescence spectrometry (XRF) Jetstream M6 from Bruker with a rhodium anode in the X-ray tube at 50 kV and 200 µA with a 100 µm-thick beryllium window. The beam diameter was 450 µm. The target was placed horizontally at a working distance of 2 mm. The spectra recording time was 200 s, with a maximum count rate of 96 kcps. Data were processed with the Esprit software developed by Bruker [23].

### MEB-EDS

The coating sample was embedded in a polyester resin ESCIL-SODY 33, pre-polished with SiC papers, to obtain a transversal section. Analyses were then performed using Scanning Electron Microscopy with Energy Dispersive X-ray spectroscopy (SEM-EDS) with the JEOL-JSM IT 300 instrument (mode 'HighVacuum', WD=10 mm, an energy beam of 20 keV, mode BED-C) and an X-ray microanalyzer X-MaxN (Oxford). The results were processed with Aztec software (Oxford).

### Raman

Two different Raman instruments were used. The micro-spectroscope Raman confocal INVIA Renishaw with a laser source of 532 nm was used for the black layer of the transversal section of the coating (see "General description of the lacquer layers"). The microspectroscope Raman with a laser source of 785 nm from BWTek was

<table><caption>**Table 2** Description of the sub-samples Q5-1 to Q5-3</caption><thead><tr><td>Sub-sample</td><td>Location</td><td>Description of the layers</td></tr></thead><tbody><tr><td>Q5-1</td><td>Coating crack near the foot pool</td><td>Wood under the black lacquer</td></tr><tr><td>Q5-2</td><td>Coating crack near the foot pool</td><td>Black lacquer</td></tr><tr><td>Q5-3</td><td>Coating around the foot pool</td><td>Reddish lacquer</td></tr></tbody></table>

used for the red layer of the transversal section of the coating (see "General description of the lacquer layers"). The systems were equipped with an optical microscope (confocal mode, focus × 50).

### ¹⁴C analyses

#### Sub-sampling of the coating

Q1, Q2, Q3 and Q4, were sampled using a cleaned chisel (Fig. 3). The multi-layer lacquer sample Q5 (see "General description of the lacquer layers") required a more elaborate mechanical treatment using microchisels (0.125 mm, 0.25 mm and 0.5 mm) in order to produce separate ¹⁴C measurements on: (1) the wooden support, (2) the black preparation layer and (3) the reddish finishing lacquer (Table 2). Solvents, commonly used by restorers to separate layers, were excluded because they induce carbon contamination. The black lacquer sub-sample Q5-2 was isolated from the wooden sub-sample Q5-1 using a microchisel on sample Q5 under binocular microscope (Table 2). The reddish lacquer layer sub-sample Q5-3 was collected in-situ using microchisels under binocular microscope after removal of a light brown film of dust by scraping with a microchisel (Table 2).

### 3.3.2. Chemical pretreatment for ¹⁴C dating

The wooden and silk samples were treated with the classical AAA chemical protocol suitable for wood and charcoal [24] as follows: (i) HCl 0.5 M (room temperature) and rinsing with ultrapure water until pH=5, (ii) NaOH 0.1 M (room temperature) and hot rinsing (80 °C) until pH=5, and (iii) HCl 0.5 M (room temperature) rinsing until pH=5. As dust was expected to be the potential lacquer contamination, Q5-2 and Q5-3 underwent acid treatment with HCl 0.5 M, at ambient temperature and rinsing until pH=5.

Chemical glasses and protective aluminium foils were previously baked out at 450 °C during 6 h, making them carbon-free. All chemicals were of ultrapure quality, and water was ultrapure (MilliQ grade).

To control the impact of chemical treatment and of the combustion, we also ran in-house "blank" (AfSud, a 70 kyr charcoal from Border Cave, South Africa) and
<figure><img src="image_6.png" /><figcaption>**Fig. 4** A (From the left to the right) Image taken by optical microscopy of the two successive layers of the coating sampled on the back side of the *qin*. SEM image of the transversal section of the coating of the *qin*; B (from the left to the right) cartography EDS with the distribution of the main elements in the two lacquer layers of the transversal section. Cartography EDS with the distribution of the minor elements</figcaption></figure>

international standards (wood—SIRI G at 378±39 BP [25]).

**CO₂ conversion and physical measurement**

The mass spectrometer ECHoMICADAS was used to measure the ¹⁴C activity of each sample [26, 27]. All the samples (from 40 to 160 µgC) were directly injected into an elemental analyser (EA) coupled with the MICADAS gas source through the gas ion source interface (GIS) [28]. The red lacquer sample Q5-3 was an exception and was injected as a gas into the MICADAS gas source through the GIS by tube cracking [29]. CO₂ was obtained off-line by combustion under pure O₂.

Ages were obtained from ¹⁴C measurements using Bats software by comparing ¹⁴C/¹²C ratios with OXII standards [30]. Most of the samples provided several measurements, but results were statistically combined.

The mean age of the sample then derives from the mean of the individual measurements, which pass the $Chi^2$ test, and is associated to the maximum between the $Chi^2$ reduced error and the standard deviation between the median of the individual measurements. Results are expressed in F¹⁴C as recommended by Reimer et al. [31] and provided as ¹⁴C ages (BP) following Stuiver and Polach's convention [32]. Probability distributions of calibrated ¹⁴C ages were generated using OxCal v4.3.2 [33] based on the IntCal20 calibration curve [34].

**Results**

**Material characterization**

**General description of the lacquer layers**

The optical microscopy revealed that the lacquer on the back side of the *qin* comprises two successive layers: (a) a heterogeneous black layer of around 1 mm with greenish
grains applied on the wooden support, (b) a homogeneous reddish surface layer of 35 µm lightly covered with a dust deposit (Fig. 4A). According to measurements using XRF, the two layers comprise mainly iron and copper inorganic elements.

### The black lacquer

This layer is black under visible (VIS) and infrared (IR) rays using VIS/IR/UV imaging. Hence, it contains a black pigment absorbing VIS and IR rays, which cannot be iron oxide since it reflects IR rays. We deduced that the pigment is most likely a carbon black: soot, charcoal, stone black, ivory black, vine black or bone black. Respectively using SEM-EDS and Raman spectroscopy, the matrix was identified as being mainly constituted of a filler made of bone black ($Ca_3(PO_4)_2$) with coarse-grained malachite ($CuCO_3(OH)_2$) (Fig. 4B). SEM-EDS analyses also detected silica $SiO_2$, ochres ($FeOOH$, $Fe_2O_3$) with potassium and magnesium aluminosilicates (Fig. 4B).

### The red finishing lacquer

This layer is red under visible (VIS) and slightly reflective under infrared (IR) rays using VIS/IR/UV imaging. Since XRF analyses applied on the sample Q5 mainly detected Cu and Fe, we first surmised that the red pigment could be an iron oxide. However, using SEM-EDS and Raman spectroscopy (Figs. 4, 5, 6), the red layer was identified as being mainly constituted of a mercury sulfide (HgS) most likely from the mineral named cinnabar accompanied by sparse particles of pure sulphur (S) (Fig. 4B).

### ¹⁴C dating results

The sample Q5-2 on the ash lacquer was thick enough to perform four measurements using radiocarbon dating (Additional file 1: Table S1, Fig. 7a). The heterogeneity of these measurements with a weak $A_{comb}$ of 5.4% is consistent with the composition of the lacquer ash layer as a mixture of several solids. The ¹⁴C dating mean value obtained [69AD–245AD] is incompatible with the historical information gathered on the "Qiulai" *qin*.

The wooden samples Q1, Q2, Q3 and Q5-1 yielded similar ¹⁴C results. The combination of the results using the "combine" option of Bayesian modelling [33] gave a high agreement index $A_{comb}=114.1\%$. It can be concluded that the wood pieces chosen for the manufacturing of the *qin* are contemporary. The tree or trees used grew and were cut during the [1458AD–1528AD] or [1552AD–1634AD] intervals (Additional file 1: Table S1, Fig. 7b).

The silk string sample Q4 and the red lacquer sample Q5-3 present similar ¹⁴C results (Additional file 1: Table S1). The combination of these measurements,

acknowledged by a high $A_{comb}$ value of 110.9%, highlighted that the silk strings and the red lacquer are contemporaneous, which might provide the last period of lacquering and changing of the strings on the *qin*. Considering that the presence of the *qin* in the CNAM collections is attested since 1849 (*terminus ante quem* in the Bayesian analysis), this probable last maintenance in playable condition might be included in the following intervals: [1659AD–1699AD] (25.0%), [1721AD–1814AD] (66.6%) or [1834AD–1848AD] (3.8%) (Fig. 7c).

## Discussion

### Characterization of the wooden body

The radiocarbon results are consistent with a traditional practice of reusing a symbolic wood when making a *qin*, as explained in "Abiding with Antiquity", c.1860 [3]. The radiocarbon dating results provide a significant hiatus, that could reach several centuries, between the dating of the wood in the [1458–1528] or [1552–1634] intervals and the dating of the silk string and red finishing lacquer (Fig. 7). The hiatus is relevant to the Chinese tradition which symbolically associates the material quality of "a very old *tong* wood" with the quality of the sound. This virtue of "antiquity" is cited in the "Twenty-Four Flavours of *qin*", ca. 1641, and detailed in the introduction by Goormaghtigh, as part of the aesthetic canons [4]. Such a music appreciation is still controversially present in the modern practice of carving *qin* in a wood that has been stored for more than a hundred years [36]. However, the storage of wood through several generations of *qin* makers is not attested in the past.

The dating hiatus between the wood on the one hand and the red lacquer and string on the other cannot be due to the sun-drying of a multi-century old tree trunk. The wood used to make the *qin* should be porous, light, even and smooth without the knots or distended and twisted fibers caused by the influence of the sun or the wind on the growth of the wood, as mentioned in early written sources. Therefore, secondary branches are preferentially selected according to an appropriate age and height [22]. The Tang period poems (618–690, 705–907) studied by You [14] confirm the preference for secondary branches rather than the trunk, except in the case of a tree less than a decade old.

"As for the material that should be used, it should be from younger branches; that is, branches that are close to the top of the trunk. If the tong is not old, then its young branches will certainly not be big. Choose wood far away from the ground, with the top blown by wind and dried by sun. It should
<figure><img src="image_7.png" /></figure>

<figure><img src="image_8.png" /></figure>

<figure><img src="image_9.png" /><figcaption>**Fig. 5** The upper spectrum correspond to the homogeneous red lacquer (b), and the following spectra to the heterogeneous black layer (a) and were obtained using SEM-EDS</figcaption></figure>
<figure><img src="image_10.png" /></figure>

<figure><img src="image_11.png" /></figure>

<figure><img src="image_12.png" /><figcaption>**Fig. 6** (From the top to the bottom) Raman spectra for the identification of mineral pigments in the finishing lacquer (b) with some red grains showing the presence of cinnabar, and in the black lacquer (a) with several coarse green grains showing the presence of malachite, and with grains of bone black [35]</figcaption></figure>
<figure><img src="image_13.png" /><figcaption>**Fig. 7** Calibrated ¹⁴C ages of the "Qiulai" *qin*. The probability distribution diagrams of: **a** sub-samples of the black lacquer Q5-2; **b** wooden samples of the back side of the foot Q1, the pillar Q2, the foot Q3 and the wood support under the lacquer Q5-1 with their respective Bayesian modeling combination in black, and the upper diagram in blue of the combination of all wooden parts; **c** sub-sample of the upper lacquer in red Q5-3 and sub-samples of the silk string in blue Q4 with their respective Bayesian modeling combination in black, and the upper diagram in black of the combination of the red lacquer and the silk string parts taking into account the event of the entry of the *qin* in the CNAM collection prior to 1849</figcaption></figure>
be moistened by frost and dew with plenty of pure air. Furthermore, it is good if the material is facing southeast, (because) "the Great Brightness (the sun) is born in the east".<fnref n="9" />

The Book of Odes<fnref n="10" /> states: "The wutong grows there on those slopes and faces the sun"<fnref n="11" /> [3]

The interpretation of the ¹⁴C results as due to the reuse of wood is reinforced by the fact that the "Qiulai" *qin* is not made from a conventional *tong* species, but from a porous resinous wood from the *Taxus* family. Considering that the changes in Li Bai's poem carved on the back side are a subtle and skilful adaptation to this particular *qin*, the replacement of the sinogram *tong* 桐 by *bai* 柏 for resinous woods of cedar or cypress may be linked to this manufacturing choice. Other wood species than *tong* tree can be used, especially old building timbers:

"As for good quality in old materials, (...) one can not be certain that it will be tong wood. Some other kinds of wood are also all right. The wood is useable as long as it is light and porous, crisp and smooth. (...) As for beams, pillars, and router rafters, the ancients used tong for some of these. But it has to have survived for a couple of hundred years. If at an old monastery or temple on a high precipice or cliff, or by a waterfall, or stream shore in high, spacious and quiet regions, absolutely cut off from the cacophony of the everyday world, there one can find good material for the qin. Naturally it will have a special sound. "[3]

As a testimony of this practice during the nineteenth century, the wood of the "Yun He" 雲龢 qin kept at the Musical Instruments Museum, Brussels (Coll. MIM, n° inv. 0760) has been identified as originating from Jing Hui 淨慧寺 Temple in the Guangzhou province (Canton) thanks to ink inscriptions on the back side [37]. This unfulfilled epigraph also indicates that the qin was built by the maker Li Menggeng 李夢庚 whose life is poorly known, but who partly coincides with the reign of Daoguang 道光帝 (1820–1850). The entry of this qin in the MIM collections is dated between 1881 and 1886 according to the inventories.

The ¹⁴C results for the wood of the "Qiulai" *qin* are consistent with a long tradition in *qin* making that consists in reusing old wood with a highly symbolic and spiritual

value, whether during the period of activity of Tang Kai or in the early nineteenth century before the recorded presence of the *qin* in the CNAM collection in 1849.

## Composition of the lacquer ash layer

The radiocarbon dating and material characterization of the "Qiulai" *qin* lacquer ash layer revealed a mixture of two major solid ingredients, bone black and malachite, consistent with the use of powdered deer antler and crushed stones mentioned in the *Qinfang* c.1641 and the *Yuguzhai Qinpu* c.1860 [3, 4]. The lacquer ash layer is located between the wood body and the red lacquer. However, the heterogeneous ¹⁴C results on this layer with a mean value of [69AD–245AD] are not compatible with the expected period of the making of the *qin*. Based on the material analyses, the age obtained might be due to the mixing of carbon from ingredients contemporary with the lacquering of the *qin* (F¹⁴C = 0.976 ± 0.007, value of the red lacquer) with 20% of geological carbonates from malachite residues (F¹⁴C = 0) remaining after acid etching during the chemical pretreatment of the subsample Q5-2.

The detection of carbon and phosphorous in the lacquer ash layer of the "Qiulai" *qin* does not differentiate deer antler ash from deer or another animal bone ash. Li et al. [13] also reported that the detection of Ca₃(PO₄)₂ merely indicates the presence of bone ash regarding the "Yu Quan" *qin* from the Yuan Dynasty. However, traditional recipes comprising the raw sap of the lacquer tree and the ash of deer antlers *lujiao shuang* 鹿角霜 are mostly cited [14, 38]. According to the *Yuguzhai Qinpu* c.1860, "Whenever others put on the powder and lacquer they use a cattle horn comb (...). The powder; that is, deer horn *shuang*霜, (...) should be ground fine."

The detection of the coarse grains of malachite is suggestive of the *qin* makers' practice of occasionally adding fragments of metal or stone to the lacquer ash layer in accordance with the symbolism of the carillon and lithophone so as to obtain the ideal acoustic properties, as discussed by Goormaghtigh [4] based on the following citation in the *Qinfang* c.1641: "The fingers struck the strings as if they drummed metal or stone, without any interference from the neighboring strings. It is in this search for limpidity that one goes beyond all sounds". Chang [39] mentioned that the highly estimated lacquer of *qin* made in the Tang Dynasty (618–690, 705–907) corresponded to the Asian lacquer technology consisting in adding scraps of metallic or stone fillers. A mixture, commonly named "eight precious ash" lacquer *baobaohui* 八寶灰漆<fnref n="12" /> by *qin* makers, is made of fragments of gold, copper, bronze, porcelain, silver, mother-of-pearl, malachite, pearl, jade, agate, coral or seashells [8].

<footnote n="9">⁹ Da ming sheng yu dong 大明生於東 Liji 禮記 (Book of Rites), Liqi 禮器 (Instruments of rites, 28, https://ctext.org/liji/li-qi/zh).</footnote>

<footnote n="10">¹⁰ "wutong sheng yi, yu bi chaoyang 梧桐生矣, 於彼朝陽。" Shijing 詩經, 252 https://kknews.cc/culture/5lly9g3.html.</footnote>

<footnote n="11">¹¹ The *Yuguzhai Qinpu* http://web.cecs.pdx.edu/~jrb/chin/v22/v22.htm#_ftnref7.</footnote>

<footnote n="12">¹² http://www.silkqin.com/03qobj/strings/shuchee1.htm.</footnote>
Powdered deer antler and crushed stones are not ingredi-
dients only used for *qin* lacquers but can be found in
Asian lacquers of other objects [40]. For example, a lac-
quered tray from the Ming period (1368–1644) presents
surface "snake-belly cracks" as for *qin* from the same
period, which could be due to the use of similar com-
pounds such as powdered deer antler, bone, horn, ash,
sandstone, or ceramics [41]. Our results are consistent
with the traditional composition of the lacquer ash layer
of *qin*; however, due to the long tradition spread over sev-
eral dynasties, a more accurate attribution is not possible.

The silk string and the red lacquer dating

The analyses revealed that the remaining silk string and
the red lacquer are contemporaneous, meaning that the
last lacquering and maintenance in playable condition
occurred in China during the Qing dynasty (1644–1912)
since the radiocarbon dating yielded the [1659–1699],
[1721–1814] or [1834–1848] intervals. According to our
investigations, three hypotheses are currently available
for the attribution of the period when the "Qiulai" *qin*
that entered the CNAM collection before 1849 was built:
(i) it was collected, dated and signed by Tang Kai in 1712,
(ii) it was made by Tang Kai in 1712, or (iii) it is a well-
informed late eighteenth-nineteenth century copy using
an old wood carved in China.

The absence of typical cracks duanwen 斷紋 on the lacquer is surprising. Cracks may begin to appear a hundred years after the making, and the shape of the cracks can be used for the relative dating of the *qin*. Re-lacquering or restoration of the "Qiulai" *qin* by successive owners can be considered during the [1721–1814] or [1834–1848] intervals, as such practices have already been observed on other ancient *qin*.<fnref n="13" /> For example, the "Mingfeng" 鳴鳳 *qin* is known to have been recut and re-lacquered by Tang Kai [20]. The cracks on the "Xianren you" *qin* from the Song period (1127–1279) have been wiped out by restoration [42]. However, the cracks are not necessarily proof of antiquity even if this is the reason why Chinese connoisseurs estimate them. Like the "Qiulai" *qin*, the "Yun He" *qin* that entered the MIM collection c.1880 presents no surface cracks either.

The "Qiulai" *qin* shows 18th-century features, and
material characterization analyses as well as ¹⁴C results
are consistent with the traditional practices of the *qin*
makers from this period as described in written sources
[3, 4]. The authenticity of this *qin* is credible. Indeed,
the Qing dynasty period was rich in cultural exchanges

between China and France under the Ancient Regime.
French sinophilia during the 18th Century Enlighten-
ment is also well-known under the reign of Qianlong
(1735–1796). China’s tolerance toward Christianity
allowed the establishment of Jesuits whose exchanges
with the Académie Royale des Sciences provided infor-
mation on Chinese techniques of the time. For example,
the Jesuit Pierre Nicolas Le Chéron d’Incarville (1706–
1757) sent a memoir to the Académie in 1760 mention-
ing the use of resin tree and calcined deer bones in black
Chinese lacquers [43]. The sending and the studying of
*qin* in the eighteenth century in France is attested. For
example, the Jesuit priest Joseph-Marie Amiot (1718–
1793) sent a *qin* to M. Bertin for his cabinet of curiosities
[44], as reported in his correspondence with the Aca-
démie des Sciences [45]: “The first is a *Kin*<fnref n="14" /> with seven
strings, unlike those of today (...). It is made of a single
piece of wood”.

If the "Qiulai" *qin* was made by Tang Kai and kept its
original lacquer, then it was manufactured in the [1659–
1699] interval, since the ¹⁴C dating results on the red
lacquer provide intervals that do not include the date of
1712 carved on the back side of the *qin*. The carving of
inscriptions on a *qin* traditionally took place after the
instrument had been made and even played for several
years.

Conclusions

The most significant findings that emerge from this study
are that the *qin* rediscovered in the CNAM collection has
exceptional characteristics that are consistent with cur-
rent knowledge about eighteenth-century *qin* manufac-
ture. Several aspects might contribute to the testimony
of the *qin*'s authenticity: its shape, the carved inscriptions
including Tang Kai's seal, the consistent ¹⁴C dating of the
different materials of the *qin*, the choice of the wood, the
lacquer composition and stratigraphy, while the archival
documents and the absence of cracks duanwen 斷紋 pro-
vide additional clues testifying that the *qin* was scarcely
played and well-preserved in the French collections
prior to 1849. While interdisciplinary investigations on
early Chinese zithers are seldom used, our results were
achieved thanks to the combination of material char-
acterization techniques, advanced radiocarbon dating
technology and museum expertise confronted with early
Qing dynasty written sources. This research project con-
stituted a unique opportunity to study one of the most
remarkable *qin* kept in Europe.

<footnote n="13">¹³ For example: Signatures, Inscriptions, and Markings of "Xiangpu's Treasure" Guqin (古琴) translated by Hui Fang, Dept. of Asian Art, December 2014. The Met, 2014 https://www.metmuseum.org/art/collection/search/670501 (accessed May 16, 2021).</footnote>

<footnote n="14">¹⁴ *Kin* is the name given by the Jesuit community under the Ancient Regime to *qin*.</footnote>
**Supplementary Information**

The online version contains supplementary material available at https://doi.org/10.1186/s40494-021-00563-8.

**Additional file 1: Table S1:** Conventional, calibrated and modelled ¹⁴C ages obtained for the "Qiuilai" qin using OxCal4.3.2 [33] based on IntCal20 [34]. Statistical results of Bayesian modelling are shown in the last four columns. **Fig. S1.** (from the top to the bottom) ATR-IRTF spectra of the finishing lacquer (b) and the black lacquer (a) with a noised signal, especially for the black layer due to the presence of inorganic elements such as copper, gypsum or aluminosilicates. The pics are relevant with lacquer spectra (database IRUG http://irug.org/search-spectral-database) [46]. Data were recorded within the range 4000–500 cm⁻¹ using a spectrometer Nicolet 6700 equipped with a diamond ATR module (SMART endurance) and with the OMNIC software (Thermo Fisher Scientific) [47].

**Acknowledgements**

The authors warmly acknowledge Lucie Rault and Benjamin Meunier for translations from Chinese, Didier Brissaud for the Raman spectroscopy analysis, Marie Radepont and Oulfa Behadj for in situ XRF and FTIR analyses, Francois Thil and Nadine Tisnérat-Laborde for their help in physical measurements and validation of ¹⁴C data. The authors would also like to thank Philippe Bruguière Julie Chang, Claire Chantrenne, Simon Debierre, Jing Han and Wang Yuegong for thoughtful indications and suggestions and Lucie Rault and Francois Picard for reviewing this article. Authors are grateful to Elizabeth Rowley for editing the English of the article. Finally, the authors are indebted to two anonymous reviewers whose comments helped to improve the original manuscript.

**Authors' contributions**

MGD and SV designed the study with input from CH and AGM. CF was responsible for the loan of the object and agreed with the way the study was conducted. MGD, AGM, SV, CF are responsible for the historical and scientific documentation of the instrument. Radiocarbon and statistical analysis were performed by CH and MGD. TF prepared cross sections and performed material characterization on samples. TF and WN discussed the results and interpreted them in the context of radiocarbon dating. The global interpretation was the result of a collective thinking of all authors. MGD wrote the manuscript with input from all co-authors. All authors read and approved the final manuscript.

**Funding**

This work is part of Ph.D. research funded by the Fondation des Sciences du Patrimoine, and supported by the Musée de la musique (Paris), the Laboratoire des Sciences du Climat et de l'Environnement (Gif-sur-Yvette), the Centre de Recherche sur la Conservation (Paris) and the Université de Versailles-Saint-Quentin-en-Yvelines.

**Availability of data and materials**

All data generated or analyzed during this study are included in this published article. Raw data (including spectra) are available upon request from the authors.

**Declarations**

**Competing interests**

The authors declare that they have no competing interests.

**Author details**

¹Laboratoire des Sciences du Climat et de l'Environnement, UMR 8212 CEA CNRS UVSQ, Université Paris-Saclay, 91191 Gif-sur-Yvette, France. ²Centre de Recherche sur la Conservation (CRC), Muséum National d'Histoire Naturelle (MNHN), Ministère de la Culture, CNRS USR 3224, 36 rue Geoffroy-Saint-Hilaire, 75005 Paris, France. ³Musée de la Musique, Cité de la Musique - Philharmonie de Paris, 221 avenue Jean Jaurés, 75019 Paris, France. ⁴Curator, Musée de la Musique, Équipe Conservation Recherche, CRC, MNHN, CNRS USR 3224, Ministère de la Culture, 36 Rue Geoffroy-Saint-Hilaire, 75005 Paris, France.

⁵Laboratoire de Recherche des Monuments Historiques (LRMH), 29 rue de Paris, 77420 Champ-sur-Marne, France. ⁶Curator, Musée des Arts et Métiers (CNAM), 60 rue Réaumur, 75003 Paris, France.

Received: 24 June 2021 Accepted: 13 July 2021

Published online: 24 July 2021

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