Study of a Portuguese 18th century manuscript: “Relaçam das madeiras descriptas, que se comprehendem no termo da villa de Caxoeira

The manuscript “Relaçam das madeiras descriptas, que se comprehendem no termo da villa de Caxoeira”, finished in 1790, is a report from a Portuguese expedition in Brazil, for the Portuguese Crown. 46 trees found in Brazil are illustrated and the use the people made of them is described. To paint the trees, green and ochre colours were applied. Some of the greens show the typical degradation displayed by cooper pigments, with consequent paper corrosion, but others are in very good condition. In order to understand this fact, the pigments used to produce the green colours were fully characterized by m-FTIR (Fourier Transform Infrared Spectroscopy) and m-EDXRF (energy dispersive spectroscopy of X-ray fluorescence). It was found that the non-degraded greens are a mixture of Prussian blue with gamboge yellow and the others are based on verdigris. A full reconstruction of the non-degraded green paints was performed using parchment glue as binder and its infrared spectra fully matched the originals.