Of the six refining recipes for silver ores implemented on an industrial scale prior to the end of the 19c, three were the product of an extremely fruitful period of invention and innovation that took place around Potosi, in present day Bolivia, during the two decades that span the turn of the 16th century. Without these breakthroughs in the use of mercury, the environmental toll of relying on lead to refine silver ores would have been much worse, yet the question remains of their impact on present day levels of legacy mercury in our environment.
Saúl Guerrero holds a PhD (Polymer Physics) from Bristol University, U.K. (1980), an MA (Global History) from Warwick University, U.K. (2009) and a PhD (History) from McGill University, Canada (2015). After teaching and research on polymers at the Universidad Simon Bolivar, he worked for various companies of Petróleos de Venezuela, S.A. Since 2010 he has focused on interpreting the historical primary sources on colonial silver refining using a multidisciplinary approach that combines chemistry, geology, environmental science and industrial architecture. He is currently an Honorary Associate Professor of the Australian National University and works from home in Caracas, Venezuela. For a selection of his most recent research see Silver by Fire, Silver by Mercury: A chemical history of silver refining in New Spain and Mexico, 16th to 19th Centuries, Leiden: Brill, 2017; with D. Pretel, “Silver Refining in the New World: A Singularity in the History of Useful Knowledge,” History of Science, July 31, 2023 ; with L. Schneider, “The Global Roots of pre-1900 Legacy Mercury,” Proceedings of the National Academy of Sciences, 120 (31), 2023, e2304059120.
