POTASH,SALTPETER AND TAR

Quantitative calculations on the use of natural resources provide valuable tools, which can give new insights to old questions and rise new ones. In this article, I compare the wood consumption in the production of potash, saltpeter and pine wood tar in 19th century Finland. My calculations shows that in the 19th century the cumulative wood consumption in the production of potash might have been higher or at least on the same level as in the production of tar, while the production of saltpeter consumed only a fraction. In the 1830s their combined wood consumption reached the level of slash‐and‐burn cultivation.     

The politics of water security in southern Saskatchewan

This paper examines long-term water and resource management in Saskatchewan. Agriculture has long sustained Saskatchewan's economy, but the province experienced a resource boom in oil and potash in the 2008–2015 time period. What potential water-related risks are posed by oil and potash? And is the province able to balance the short-term economic gains of these developments with the long-term goal of water security? The research is based on interviews with policy elites in the province of Saskatchewan and argues that four factors explain why the government continues to favour industry over water security: low-issue salience, economic and political interest, ideology, and political culture.     

Identification of PbO (BaO) faience from an early and middle Warring States period cemetery at Zhaitouhe,northern Shaanxi,China

Low‐temperature vitreous materials fluxed with lead (and barium) appeared in the early Warring States period (c.fifth century bce ) in ancient China. A range of lead vitreous products fluxed with the same agent, including faience/glass beads, glazed pottery and Chinese blue (purple) pigment, were developed subsequently. This study carries out scientific analysis of six vitreous beads unearthed from the Zhaitouhe cemetery site in northern Shaanxi dating to the early and middle Warring States period to investigate their chemical composition, microstructure and coloration. The lead (and barium) vitreous beads identified here are some of the earliest lead vitreous materials discovered in China so far, and therefore important for the study of the development of lead vitreous technologies in ancient China. This paper also points out that it is meaningful to evaluate the lead glass, glazed pottery and barium copper silicate pigments as a whole technological assemblage given their close relationships.     

Iron-57 Mössbauer spectral studies of medieval stained glass

⁵⁷Fe Mössbauer spectral data for six excavated and two simulated medieval stained glass samples are reported. Iron-containing precipitates are observed in the two simulated medieval glasses and are responsible for the amber colour of these samples. The ferrous/ferric ratio of the other samples is dependent on the glass composition and glass making conditions. The green glasses are associated with the presence of both ferrous and ferric iron, the ratio being very similar in three of the glasses studied, while in the purple and emerald green glasses the iron which is constitutionally incorporated in the glass is solely in the ferric oxidation state. The UVvisible spectra of some of the glasses are used to assist in interpretation of the colourant action of iron, and the role of Mössbauer spectroscopy in linking separate glass fragments with a common source is also indicated.