Thursday 19 July 2012

Investigating objects

Last week, two of our project partners visited us in Oxford.  Professor Richard Evershed from the University of Bristol came with his postdoctoral student, Lucy Cramp, to take samples of resins from various objects in the Cook-voyage collections.  They will use powerful techniques such as gas chromatography, followed by mass spectroscopy to try and give more information about which plant resins were used.  These analytical techniques require very small samples, and, under the microscope, there are usually tiny loose pieces of resin which can be carefully removed using the end of a scalpel blade.

Removing a sample of resin from a chest ornament, Marquesas (1886.1.1269)

Andrew Charlton from the Food and Environment Research Agency (FERA) also came to the museum last week.  Andrew specialises in the effect of pesticides on wildlife, and the purpose of the visit was to work out a method of taking surface swabs from objects so that he can test them for pesticides residues.  We know that objects in the Pitt Rivers, as in all other museums, were routinely sprayed with pesticides, including arsenic, mercury and more recently developed chemicals such as DDT, to prevent insect attack.  We are interested in finding out if there are residues of these chemicals on the surface of museum objects.  The Cook-voyage collections have been in Oxford since the 1780s so we'd expect a wide range of pesticides to have been used on them.

Jeremy with Kloe Rumney, conservation intern from Cardiff University, taking samples from the surface of a Tongan mat (1886.1.1175)