Qadhat—a comparative study of ancient and new lime mortar from the Marib province/Yemen

Qadhat is the name for a lime mortar in Southern Arabia. Its usage has a long tradition. This work describes physical and mineralogical properties of ancient, historical and new samples, which seem to have been produced the same way. XRD, thin sections and SEM analyses show the similarity of the material. It consists of aggregates of volcanic material that are rich in volcanic glass and lime as binder. The production process includes several hours of crushing the material, which produces fine-grained splinters of aggregates in the binder matrix and gives the mortar a high stability. A weathering test with sodium sulphate on different samples confirms that the stability of this mortar is the result of the production process.     

Pigments, dyes, and black enamel—the colorants of reverse paintings on glass

Nondestructive analyses of medieval reverse paintings on glass revealed the same dyes and pigments customarily used in panel paintings. However, there is one exception: the black colorant is not a carbon-based pigment, but black enamel. In this respect, the stylistic as well as the technical influence of stained glass artwork can clearly be seen on reverse paintings on glass. However, there is a crucial difference: in reverse paintings, the black enamel is not fired onto the glass but painted (cold painting). Additional analyses confirmed these findings. Based on these results, the art form “reverse painting on glass” has technically to be characterized as a mixture of “stained glass” and “panel painting” that nonetheless develops into a genre of its own.     

Forests for cotton: Institutions and organizations in Brazil's mid-twentieth-century cotton boom

The western region of São Paulo state, Brazil, became one of several sites of global cotton production during the first half of the twentieth century in response to increased global demand and fears of cotton shortages. The cotton boom tapped a ‘forest rent’ that helped Brazil rise to become the largest producer in Latin America, providing both export revenue and critical raw material to a growing industrial economy that would become the largest in South America. This paper uses an organizational and institutional perspective to analyze causes and effects of the mid-century cotton boom that centered on São Paulo state. Organizations and institutions relating to cotton production are considered using oral histories, judicial documents, agronomic texts, and the sediment record in small catchments as empirical evidence. The state dramatically reformed some organizations to provide the key inputs to cotton production, while most contemporary observers ignored institutions, such as sharecropping and tenant farming, that supported cotton. São Paulo's institutions and organizations were characterized by the borrowing and adaptation of existing labor institutions, the creation of new state organizations that subsidized elite producers, and the weak development of institutions or organizations in response to soil fertility issues and labor supply.