4 CONCLUSIONS

The high spatial resolution of the micro-Raman technique has been exploited in the individual identification of solid compounds amid a mixture of 4-60 �m-sized particles that constituted a white bloom on an 1876 print artifact. No sample preparation was required. In this instance, the powdery deposit brushed off the surface of the print artifact was simply placed on a microscope slide and directly analyzed. The Raman spectra of the individual particles were recorded and compared with those available in our spectral database for identification. The white deposit was predominantly a mixture of calcium carbonate and paratoluenesulfonamide (almost certainly arising from a previous conservation treatment by chloramine-T), with small amounts of black carbon, quartz, and microsized cellulose fibers from the paper matrix. None of the solids identified was a toxic pesticide residue, as had been feared, and the conservation treatment of this valuable artifact is now under way. It is noteworthy that the use of chloramine-T as a paper-bleaching chemical has now been discontinued due to a proven problem of severe degradation of the cellulose fiber.

ACKNOWLEDGEMENTS

The authors are indebted to the Adelaide City Archives, Adelaide, South Australia, for providing permission to publish this data.