A non-invasive approach to identifying wood species in historical musical instruments

Identifying the wood species is an important step in the process of studying and preserving historic wooden artefacts. Identification procedures normally applied in cultural heritage contexts are unsuitable for musical instruments, as sampling might alter the aesthetics and functionality of these historically and culturally valuable instruments. Furthermore, macroscopic identification, through the naked eye or a lens, is often inadequate. It is necessary, therefore, to adopt a non-invasive approach, which renders visible the greatest number of anatomical features possible. The purpose of this study was to evaluate the feasibility and reliability of identifying the wood of historical artefacts using microscopes with high magnification and reflected light together with polarized light filters. A total of 117 musical instruments from the “Luigi Cherubini” Conservatory's collection, preserved at the “Galleria dell'Accademia” Museum in Florence (Italy) were examined as case study. The collected data here presented demonstrate that many anatomical features of the wood can be observed in situ, thanks to the portability of the instruments, and that identifying can be done indeed (in almost 6000 observations, only 8% gave no results). In cases where identifying was not possible, the problems involved: the presence of very thick coats of clear varnish, which makes it virtually impossible to see the structure of the underlying wood; the presence of a patina that conceals the wooden surface; and poor surface quality of the wood, which can falsify the appearance and size of wood cells.