The Mary Rose sample was taken using an incremental borer. This sample presented a transect across the wooden beam which formed the exterior layer of the hull. Because relatively large and well-structured volumes of sample were available for study, THM-GC-MS measurements were made using subsamples taken along the sample from the outer, exterior, "edge" and the inside "core," as an indicator of the effects of differing exposures to seawater. An additional untreated and dry sample of the Mary Rose was studied in order to gauge the effect of the PEG on preserving the wood chemistry due to burial. A representative GC-MS chromatogram is presented in Figure . Guiacyl and syringyl were identified in all the samples (Table ). Peak areas were used to calculate the S/G, Ac/AlS, and Ac/AlG ratios .