This paper examines the professional trajectory of Alberto Santini Sgaluppi ("conde de Das"), an esoterist who performed in Buenos Aires and Lima in the late nineteenth century and analyzes the impact of his spectacles on diverse social actors in the two South American capital cities. We argue that individuals like Sgaluppi played a pivotal role in the spread of knowledge about nascent phenomenons linked to esoterism and hypnotism; at the same time, a close examination of his performances throws light on the development of scientific discourses and on the contours of "science" in the public sphere, beyond the conventional circle of experts.