Volume 41, Issue 1 -

This research investigates chemical alteration in the important historical pigment called verdigris, both in the form of neutral verdigris (Cu(II) (CH 3 COO) 2   .  H 2 O) and basic verdigris (Cu(II) x (CH 3 COO) y (OH) z . n H 2 O), using reference pigment powders and historically relevant “mock-up” samples exposed to artificial aging. Analytical study of model samples by combined Raman spectroscopy, X-ray diffraction and visible spectroscopy provides new evidence that clarifies and builds on the often conflicting body of literature, first in terms of analytical identification of different forms of verdigris pigment, and second by tracing the alteration of neutral verdigris in systems that link to its behavior in aqueous media on historical types of paper. Results further suggest that the historical importance of neutral verdigris as a pigment is underestimated, since commercially available verdigris throughout its heyday – from before the Renaissance through the eighteenth century – was likely to have been dominated by the more easily manufactured neutral salt. This misunderstanding may arise from pigment alteration, whereby the neutral verdigris converts to basic copper salts, or forms organo-copper complexes.

A small repository in a cathedral in Poland, storing severely damaged books, was investigated with regard to insects and fungi. Entomological and microbiological surveys were performed to estimate the extent of the infestation and the microbial deterioration of the books. Most of the books were attacked by insects although to varying degrees. They were damaged by tunnels bored by the larvae and filled with larval faeces. Some living larvae and many dead adult beetles were found in the books or in the frass. The larvae and most of the beetles were identified as the common deathwatch beetle Xestobium rufovillosum (DeGeer, 1774). The development of Xestobium rufovillosum in books is an unusual case and has rarely been mentioned in the literature. Several books in the repository were also covered by microfungi, especially by Chaetomium murorum , Ch. elatum, Myxotrichum chartarum, Stachybotrys atra and Epicoccum nigrum . The temperature in the repository varied, depending on the season of the year (2.6 °C – 26.2 °C), while the relative humidity was high (constantly above 65 %). The concentration of the fungal bioaerosol was very high (4,120 cfu/m 3 ). The article includes a list of recommendations pertaining to the elimination of the microorganisms and insects.

This paper discusses pigments used in Indian palm leaf manuscripts. Formerly it was believed that pigments for palm leaf illustrations were mostly sourced from plant extracts – a believe that is still widespread in India. This paper reports the identification of pigments of an illustrated palm leaf manuscript (eighteenth – nineteenth century) collected from the east coast of India. As Raman spectra of many pigments gave too high background noise, the identification was mostly accomplished through SEM-EDX and FTIR spectroscopy. The analytical findings indicated that both mineral colours and plant extracts were sourced for Indian palm-leaf manuscripts. Analysis indicated the use of lamp black for black, indigo for blue, vermillion for red, orpiment for yellow, china clay for white and a mixture of orpiment and indigo for green coloration in the illustrations. The data has improved our knowledge of historic pigments used in palm leaf illustrations. As some of the pigments are either photosensitive or darken due to atmospheric pollution, necessary preventive conservation measures need to be adopted.