Evaluating bone collagen extraction methods for stable isotope analysis in dietary studies

The specific purpose of this study was to compare three different collagen extraction methods commonly used in isotope laboratories conducting dietary studies. We evaluated their resultant differences in δ¹³C and δ¹⁵N, collagen quality and collagen yield. Our study was based on well-preserved skeletal material from the medieval period in Denmark. Our study shows that there is a systematic significant difference in the yield and the δ¹³C values between the three methods. Using the method of DeNiro and Epstein [DeNiro, M.J., Epstein, S., 1981. Influence of diet on the distribution of nitrogen isotopes in animals. Geochimica et Cosmochimica Acta 45, 341–351] with NaOH as cleaning agent, will, according to our study, give δ¹³C values that are on average ±0.32‰ more positive than using the ultra-filtration method [Brown, T.A., Nelson, D.E., Vogel, J.S., Southon, J.R., 1988. Improved collagen extraction by modified Longin method. Radiocarbon 30 (2), 171–177, modified in Richards, M.P., Hedges R.E.M., 1999. Stable isotope evidence for similarities in the types of marine foods used by late Mesolithic humans at sites along the Atlantic coast of Europe. Journal of Archaeological Science 26, 717–722]. The third method, which is a modified version of the second method, excluded the ultra-filtration step. This method seems to give δ¹³C values that lie in between the other methods. Our study did not show any significant difference in δ¹⁵N values. Although the differences between the methods are very small, we conclude that the use of stable isotope analysis in food determination studies requires adherence to routine methods for preparing and measuring samples.     

Some Napoleonic-style army camps from the period of the Dutch-Belgian separation (1830–1839) in the Southern Netherlands

This paper focuses on the period of the political separation of the Netherlands and Belgium (1830–1839). Both countries were in a state of war for almost a decade, which resulted in massive troop deployments along their borders and the militarisation of the landscape. The principal objects of study are the Dutch army camps at Rijen and Oirschot near the Belgian border, which to date have barely received any scholarly attention. Both camps were almost 2 km across and offered accommodation to up to 12,000 infantry soldiers. They will be studied from an archaeological-historical perspective, focusing on the spatial and social dimensions of the camps and their place in the wider landscape. The camps are representative of the final stage of pre-industrial warfare in Europe, which is characterised by a continuation of many eighteenth century and Napoleonic traditions.