The ‘Sand-Bath’ and Lithic Heat Treatment in the South African Middle Stone Age: Myth or Reality?

When heat treatment of silcrete for stone knapping was first discovered in the South African Middle Stone Age (MSA), the procedure used for it was suggested to be similar to the one used for heat treatment of finer rocks in other parts of the world: slow sand-bath heating. This comparison may have been based on published data from the fields of ethnography, experimentation and archaeology, describing sand-bath like structures and processes. In this review, I discuss whether the available data from these three fields indeed justify the suggestions that sand-bath heating was used in the context of MSA silcrete heat treatment. A careful revaluation of the available data shows that, although sand-bath heating is a widely accepted procedure that is documented in other parts of the world, understanding the earliest known cases of heat treatment in the MSA calls for another technical procedure.     

Narratives and Bodies: Culture beyond the Cultural Turn

This article offers a fresh assessment of the current condition of ‘culturalist’ international history, exploring its achievements and limitations, taxonomising its key threads and charting an agenda for the future. It argues that at its heart lie two core concerns, one with narratives and the other with bodies. Thinking in this way allows us both to tie together work which initially appears disparate – endowing a bewilderingly diverse mass of scholarship with coherence and shape – and to better grasp the project's current trajectory. It analyses how these two issues rose to prominence, discussing not only the merits and failings of previous ‘culturalist’ work but also linkages with shifting debates in historical theory in the aftermath of the ‘postmodern’ turn. It explores the contours of the important work currently being conducted under these rubrics, drawing attention where appropriate to cognate scholarship in the discipline of International Relations with which international historians might profitably engage. Understanding the significance of these two core concepts provides vital orientation in contemporary intellectual debates within international history and enables us to push them on further.     

The first direct evidence of pre-columbian sources of palygorskite for Maya Blue

Maya Blue, a nano-structured clay–organic complex of palygorskite and indigo, was used predominantly before the Spanish Conquest. It has fascinated chemists, material scientists, archaeologists and art historians for decades because it is resistant to the effect of acids, alkalis, and other reagents, and its rich color has persisted for centuries in the harsh tropical climate of southern Mesoamerica. One of its components, palygorskite, is part of modern Maya indigenous knowledge, and ethnohistoric and archaeological data suggest that its modern sources were probably utilized in Prehispanic times. Yet no direct evidence verifies that palygorskite was actually mined from these sources to make Maya Blue. Here we characterize these sources compositionally, and compare our analyses to those of Maya Blue from Chichén Itzá and Palenque. We demonstrate that the palygorskite in most of these samples came from modern mines, providing the first direct evidence for the use of these sources for making Maya Blue. These findings reveal that modern Maya indigenous knowledge about palygorskite, its mining, and its source locations, is at least seven centuries old.