Ferraz, Márcia H.M., and Ana M. Alfonso-Goldfarb. 2015. “Chemistry and the Definition and Isolation of ‘active principles’ of Plants in the Late 18th and Early-19th Centuries”. Circumscribere International Journal for the History of Science 16 (December):83-92. https://revistas.pucsp.br/index.php/circumhc/article/view/25917.