#physionomy

(Duchenne and his patient, an "old toothless man, with a thin face, whose features, without being absolutely ugly, approached ordinary triviality")

Guillaume-Benjamin-Amand Duchenne (de Boulogne) was a French neurologist who greatly advanced the science of electrophysiology. The era of modern neurology progressed from Duchenne's understanding of the conductivity of neural pathways, his revelations of the effect of lesions on these structures and his diagnostic innovations including deep tissue biopsy, nerve conduction tests, and clinical photography.

Influenced by the fashionable beliefs of Physiognomy of the 19th century, Duchenne wanted to determine how the muscles in the human face produce facial expressions which he believed to be directly linked to the soul of man. He is known, in particular, for the way he triggered muscular contractions with electrical probes, recording the resulting distorted and often grotesque expressions with the recently invented camera. He published his findings during 1862, together with extraordinary photographs of the induced expressions, in the book The Mechanism of Human Physiognomy (Mécanisme de la Physionomie Humaine).