Validating Empirical Claims of Efficiency: Adjudicating Assays, Experience, and Personal Virtue in Debates Regarding Mercury Refining Ovens in 17th-Century Huancavelica

In 1617, a Franciscan friar named Miguel de Monsalve wrote to the Iberian jurist Juan de Solórzano Pereira, then serving as temporary governor and visiting judge in Huancavelica (modern Peru), describing a new oven design he had developed for refining mercury. A manuscript compilation held at the National Library of Spain in Madrid preserves numerous missives and treatises penned by Monsalve and addressed to Solórzano Pereira, as well as records documenting an evaluation of Monsalve’s proposal carried out at Solórzano Pereira’s request by an individual residing in Huancavelica named Manuel Díez de Pineda. My talk employs these sources as a window into the methods Monsalve employed to develop his oven and to buttress his claims regarding its potential benefit. It poses the same questions regarding Diez de Pineda’s process of assessing and evaluating Monsalve’s claims. This analysis reveals that while Monsalve described his oven as the product of empirical knowledge grounded in his knowledge of materials and refining practice (and advocated the carrying out of empirical tests to demonstrate its effectiveness), Díez de Pineda’s evaluation focused on textual arguments and Monsalve’s character.