Pierre-Joseph Macquer an eighteenth-century artisanal-scientific expert

Pierre-Joseph Macquer (1718-1784) is well known as one of the major chemists in the eighteenth century as a theoretician and a teacher. He is also known for his works on dyeing. This paper presents a new face of Macquer. He proposed a theory on mordants in dyeing as early as 1775. Besides his activity at the Académie des sciences, he played an important role in Government as the commissioner of dyeing from 1766 where he established close links with artisan inventors. Académicien chimiste at the royal Manufactory of Sèvres from 1757, he was also the inventor of French porcelain. His notebooks show his organization, method, courage, passion and obstinacy in the search for the paste for hard porcelain. He also proposed an interpretation of its formation. Macquer was both a theoretician and a practical expert in dyeing as well as in porcelain making. He managed to bridge the gap between science and art.

Analytical Raman spectroscopic discrimination between yellow pigments of the Renaissance

The Renaissance represented a major advance in painting techniques, subject matter, artistic style and the use of pigments and pigment mixtures. However, most pigments in general use were still mineral-based as most organic dyes were believed to be fugitive; the historical study of artists' palettes and recipes has assumed importance for the attribution of art works to the Renaissance period. Although the application of diagnostic elemental and molecular spectroscopic techniques play vital and complementary roles in the analysis of art works, elemental techniques alone cannot definitively provide the data needed for pigment identification. The advantages and limitations of Raman spectroscopy for the definitive diagnostic characterisation of yellow pigments that were in use during the Renaissance is demonstrated here in consideration of heavy metal oxides and sulphides; these data will be compared with those obtained from analyses of synthetic yellow pigments that were available during the eighteenth and nineteenth Centuries which could have been used in unrecorded restorations of Renaissance paintings.

The use of a multi-method approach to identify the pigments in the 12th century manuscript Liber Floridus

A selection of illuminations of the 12th century manuscript Liber Floridus was analysed with Raman spectroscopy (in situ and laboratory measurements), X-ray fluorescence spectroscopy, UV-fluorescence photography and infrared reflectography (IRR). The aim of this study is to determine the pigments used, in order to search for anachronisms. Using a combination of Raman spectroscopy (molecular information) and X-ray fluorescence spectroscopy (elemental information) following pigments could be identified: ultramarine (Na(8-10)Al(6)Si(6)O(24)S(2-4)), azurite (2CuCO(3)·Cu(OH)(2)), caput mortuum (Fe(2)O(3)), vermilion (HgS), orpiment (As(2)S(3)) and lead white (2PbCO(3)·Pb(OH)(2)). Moreover, two synthetic red pigments, PR4 and PR176, and a degradation product, gypsum (CaSO(4)·2H(2)O), were present in the manuscript. To establish the origin of the modern materials UV-fluorescence photography was used. Infrared reflectography (IRR) was applied to visualise the underdrawing of the investigated folios.

J. M. Despréaux' lichens from the Canary Islands and West Africa: an account of a 19th century collection found in an English archive

This is an historical and descriptive account of 28 herbarium specimens, 27 lichens and an alga, found in the archives of Charles Chalcraft, a descendant of the Bedford family, who were dye manufacturers in Leeds, England, in the 19th century. The lichens comprise 13 different morphotypes collected in the Canary Islands and West Africa by the French botanist J. M. Despréaux between 1833 and 1839. The collections include samples of "Roccella fuciformis", "R. phycopsis" and "R. tinctoria" (including the fertile morphotype "R. canariensis"), "Ramalina crispatula" and "R. cupularis", two distinct morphotypes of "Sticta", "S. canariensis" and "S. dufouri", "Physconia enteroxantha", "Pseudevernia furfuracea var. ceratea" and "Pseudocyphellaria argyracea". The herbarium also includes authentic material of "Parmotrema tinctorum" and a probable syntype of "Seirophora scorigena". Most of these species are known as a source of the purple dye orchil, which was used to dye silk and wool.

Greek alchemists at work: 'alchemical laboratory' in the Greco-Roman Egypt

The paper focuses on the alchemical laboratory of ancient Greco-Egyptian alchemists, by taking into account especially the earliest alchemical texts (both in the Greek and in the Syriac tradition), ascribed to Pseudo-Democritus, Maria the Jewish and Zosimus. The first part analyzes the possible relationships between the workshops of Egyptian craftsmen (first of all, dyers, metals workers and glass workers) and the activity of the alchemists. The second part gives a general overview on the alchemical instruments described in the Corpus alchemicum.

[Corneal tatoo--art or science?]

The permanent colouring of disfigured corneal scars is known for almost 200 years. Because of improvement in surgical reconstructive techniques, corneal tattoing is used today only with a restricted group on carefully chosen patients, and merely for esthetique reasons.

Investigation of Livingstone's curious point

The explorer and missionary David Livingstone was identified after death by the appearances of his humerus which had been damaged in an encounter with a lion. In his writings Livingstone suggested that the consequences of the lion's attack were not as bad as he might have expected. He wondered if this was due to the fact that he was wearing a tartan jacket when he was attacked and suggested that this curious point should be investigated. This paper looks at some of the dyes used in tartans of the time and investigates their effect on the bacteria that might be present in the mouths of lions.

Simultaneous identification of natural dyes in the collection of drawings and maps from The Royal Chancellery Archives in Granada (Spain) by CE

A simple and rapid capillary electrophoretic method with UV detection (CE-UV) has been developed for the identification of five natural dyes namely, carmine, indigo, saffron, gamboge and Rubia tinctoria root. The separation was performed in a fused-silica capillary of 64.5 cm length and 50 microm id. The running buffer was 40 mM sodium tetraborate buffer solution (pH 9.25). The applied potential was 30 kV, the temperature was 25 degrees C and detections were performed at 196, 232, 252, 300 and 356 nm. The injections were under pressure of 50 mbar during 13 s. The method was applied to the identification of carminic acid, gambogic acid, crocetin, indigotin, alizarin and purpurin in the collection of drawings and maps at the Royal Chancellery Archives in Granada (Spain). The method was validated by using HPLC as a reference method.

[Dyes, indispensable tools for the 19th century's biologic and therapeutic revolution]

Born from growing organic chemistry laboratories, dyes were extensively used par textile industry before to be applied in field of biology and therapeutics. Besides their interest for diagnostic techniques due to cell visualization (Virchow, Papanicolaou), dyes allowed scientists to propose scientific hypothesis founding, in conjunction with new microscopy tools, modern basis for biology : tissue constitution, cellular and sub cellular structure, s.o. One of the brightest illustrations of these progresses is the birth of neuronal theory which due to silver print of brain tissue allowed to see intimacy of cerebral structures et propose an operating scheme (Golgi, Cajal). Therapeutic progresses born from dyes chemistry are multiple. First concentrated on the research of antimalarial drugs (Ehrlich) following the use of methylene blue, then generally, anti-infectious drugs, they gave birth to various chimiotherapeutic families: antiseptics, antiparasitic drugs, antibacterial, among which one of the most spectacular illustrations remain sulphonamides preparation.

[Natural dyes and dyeing from the XVIIth century to the birth of synthetic dyes]

After historical considerations on the state and evolution of French dyeing industry in the end of the XVIIth century to the beginning of XIXth, we find this presentation a résumé of the different states of tissues dyeing. We easily note that the techniques of dyeing. We easily note that the techniques of dyeing were very brought forward the end of the XVIIIth century before that synthetic dyes appeared in the second half of the XIXth century.

The invention of blue and purple pigments in ancient times

This tutorial review examines manmade blue and purple pigments appearing in antiquity. They were obtained by chemical synthesis from mineral starting materials and refer to chemical compounds: Egyptian Blue (CaCuSi4O10), Han Blue (BaCuSi4O10) and Han Purple (BaCuSi2O6), Maya Blue (x.indigo.(Mg,Al)4Si8(O,OH,H2O)24) and Ultramarine Blue (Na,Ca)8(AlSiO12)(S, SO4,Cl). The Egyptian and Chinese copper-based pigments are assumed to have been developed independently and are presumably an outcome of the historical developments in glazing techniques. A technology transfer from Egypt into China cannot be fully excluded but, based on the facts acquired up to now, looks less probable.

[The black reaction: an ante litteram "cognitive" biotechnology]

The black reaction, also known nowadays as "Golgi staining" or "Golgi impregnation", paved the way to the development of modern neuroscience at the end of XIX century. By this staining, the silhouette of the nerve cell appears in all its morphological complexity with all its ramifications, which could be followed and analyzed even at a great distance from the cell body. However the reaction has been fundamental for discoveries in several other areas of biomedical research: cytology, myology, bacteriology. With the aid of the black reaction, for example, it was possible to observe: the Golgi apparatus, the T system related to the function of the sarcoplasmatic reticulum, the Müller-Golgi canaliculi of the peptic glands and many more; this wide and various success is due to its character of morphological amplification of fine structures. In spite of its still controversial biochemical nature, the black reaction has been an unavoidable versatile tool in different areas of biology, so we propose to consider this method as an ante litteram "cognitive" biotechnology.

[The history of tooth dyeing]

While tooth dyeing is a disappearing custom, the pharmaceutical benefits of paan in India are now being studied for other reasons. The oral carcinogenicity of betel nuts, the traditional ingredient in paan, however, has been causing paan users to replace betel with canari or lime. As a consequence of this trend, the pharmaceutical interest of paan is no longer in betel, but in the health-promoting properties of Uncaria gambir. This article has been prepared as an interim record of the progress of the author's research into this field, and was presented in the December 2006 meeting of the [symbol see text].

Sampling and identification of natural dyes in historical maps and drawings by liquid chromatography with diode-array detection

A simple and rapid liquid chromatographic with diode-array UV-vis spectrophotometric detection (HPLC-DAD) method for identification of natural dyes has been developed. Chromatographic retention of carminic acid, indigotin, crocetin, gambogic acid, alizarin and purpurin has been studied. The mobile phase consisted of 40 mM SDS-10 mM phosphate buffer solution (pH 2.3)-0.1% TFA (eluent A) and acetonitrile (eluent B) using a programmed gradient (5% B to 95% B). Analyses were carried out on a Phenomenex, Luna 5u NH2 100(a) column (250 mm x 4.60 mm i.d., 5 microm particle) and the operating conditions were: 0.6 ml min(-1) flow rate, 20 microl volume injection and 35 degrees C column temperature. Extracts of samples of natural dyes taken from historical maps belonging to The Royal Chancellery Archives in Granada were successfully analyzed using the proposed method including a new technique for sampling.

[Injectable dyes: more than 70 years of therapeutic usage of dyes]

Synthetic dyes were first discovered at the end of the XVIIIth century (picric acid by Woulfe in 1771) and during the first part of the XIXth century: rosolic acid (Runge, 1834), mauvein (Perkin, 1856), but their development was major at the end of the XIXth century. Their therapeutic use was really starting at the beginning of the XXth century, mainly by local and oral route. It is only in the 1930's that parenteral route of administration was actually developed: methylene blue, methyl violet are some examples that were used for leprosy and filariasis, respectively. After the 2nd world war, one can observe a rapid decrease of the therapeutic use of dyes by intravenous route. Only a few dyes are still used today, such as patent blue V or fluorescein, as drugs for diagnostic use.

Liquid chromatography determination of natural dyes in extracts from historical Scottish textiles excavated from peat bogs

Textiles excavated from Scottish sites belonging now to the collections of the National Museums of Scotland, including seventeenth century textiles from peat bogs in the Scottish Highlands and Islands, were selected for analysis by high performance liquid chromatography with photodiode array detection (PDA HPLC) to detect whether any dyes remained and, if so, to identify their biological sources. Dye components were identified in 36 of the 81 samples analysed. Although it was not possible to identify the exact sources of the dyestuffs because of the wide-spread occurrence of these natural dyes components, the study has shown that textiles previously not thought to have been coloured had detectable traces of dye. Before the historical textiles were analyzed, an improved extraction procedure that combined the routine acid hydrolysis method with one using dimethylformamide (DMF) was applied. The DMF method enabled increased recovery of major flavonoid and anthraquinoid compounds, and very high efficiency of recovery of indigotin even in textiles with no colour visible, thereby complementing the acid hydrolysis method already in use. Extracts from historical thread samples were analysed by PDA HPLC using a reversed-phase gradient system comprising of a C18 column (150 mm x 4.6 mm i.d., 25 +/- 1 degrees C) with water, methanol and o-phosphoric acid at an eluent flow rate of 1.2 ml/min. A preliminary investigation to improve the detection limits further for a selection of natural dyes was made by comparing results from the 4.6mm internal diameter (i.d.) column with a narrow bore C18 column (2.1 mm i.d.). An increase in the detector response was observed for narrow-bore column proving its possibility of enhancement of sensitivity.

The long history of hematoxylin

Hematoxylin is a naturally occurring chemical used as the basis of a dye in laboratories throughout the world to stain nuclei in microscope slide preparations. This chemical is extracted from the logwood tree Hematoxylon campechianum and was discovered by Spanish explorers to the Yucatan in 1502. A vigorous trade soon developed related to growing and preparing hematoxylin for use in dyeing fabrics in Europe. In the mid 1800s, amateur microscopists first used hematoxylin to stain cellular components. Later scientists developed a wide range of techniques to demonstrate different cellular components. Hematoxylin remains the most popular nuclear stain in histology. This paper briefly describes the history of hematoxylin production and use in histology.

[Is Chevreul accountable for the backward state of synthetic dyes in France?]

Head of dying at the Manufacture des Gobelins, Chevreul presided over the French Council of Arts and Manufactures and took part in the selection committees of universal exhibitions. He was accused of lacking judgement against synthetic dyes. His correspondence with dyers shows other more determinant brakes as legislative and economic ones, against which scientist, without political power, could not act efficiently.