Volume 42, Issue 2

The grey silverfish Ctenolepisma longicaudatum is a new and serious pest spreading rapidly across Europe. Compared to the silverfish Lepisma saccharinum , it does not depend on relative humidity above 70% and thrives also in new museum buildings, modern storage depositories, apartments, and office buildings. Especially collections of graphic art, modern art on paper, photographs, but also archives and libraries are increasingly affected by this pest. Damage of paper objects has been reported by different authors and institutions across Europe. As these animals live in inaccessible cracks and crevices inside the buildings, we investigated the spread of microorganisms on living grey silverfish, to show a potential additional threat posed by this pest. In 8 locations in Austria living animals were collected with traps and placed for 10 min on agar plates which were incubated for 2 weeks. After incubation of 50 agar plates, between 2 and 20 colonies of fungi were growing on each plate. The most dominant fungal genera were Cladosporium ( Cladosporium cladosporioides clade) and Penicillium ( Penicillium glabrum, Penicillium decumbens ); also, species of the genera Aspergillus , Alternaria , Botrytis , Bartalinia , Byssochlamis , Chaetomium and Mycothypha were found. The diversity of fungi reflects the common fungal community of museums and archives. The spores and mycelial fragments of the fungi are obviously travelling on the legs and bodies of the silverfish.

Textiles are frequently used in bookbinding or for attaching pendent seals and thus they are an integral part of archival and library items. Any part of these items can be contaminated by various microorganisms. Consequently, it is often necessary to include disinfection procedures in the initial stages of the conservation process. Primarily, the agents employed in conservation must not harm the treated material. This work was concerned with monitoring the effect of selected disinfectant agents (ethylene oxide, Septonex ® , glutaraldehyde, Bacillol ® AF, butanol vapours, Acticide ® MV, silver nanoparticles, Chiroseptol ® ) on the properties and long-term stability of natural textile fibres (cotton and silk). The disinfected textiles were subjected to three kinds of artificial ageing (dry heat, moist heat, and light) and their properties were determined by means of the total colour difference, thread tensile strength and the limiting viscosity number.

Textile cords and ribbons are an integral part of archival documents with pendent seals. These textiles are frequently highly degraded, especially in case of black-dyed silk. However, their maintenance in good condition is necessary for retention of the seal and thus the legal value of the document. Methods of chemical stabilization of iron-gall inks on a paper support are promising also for stabilization of degraded black-dyed silk. This chemical stabilization is based on deacidification or the use of antioxidants or a combination thereof. The deacidification is potentially dangerous for silk because of its high stability in the slightly acidic region. Therefore the stability of silk in the alkaline pH region was measured and even long-term immersion of silk in a medium with pH 9 did not result in degradation changes. The selected reagents (methoxymagnesium methyl carbonate, tetrabutylammonium bromide, cysteine, calcium phytate and tannin) were tested. The effect of stabilization procedures was studied on artificially damaged samples of black-dyed silk containing unbound ferrous ions. The effectiveness of the stabilization procedures and their influence on the long-term stability of silk were evaluated by means of colorimetry, mechanical properties (flexural rigidity, thread tensile strength), measuring the pH of the silk surface and scanning electron microscopy.