This is not my picture but I thought it might be of interest.
Extract from the Blog .....Ruth White's Research For Art .
“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 ( Mecanisme de la physionomie Humaine).
Like physiognomists and phrenologists before him, Duchenne believed that the human face was a map, the features of which could be codified into universal taxonomies of inner states; he was convinced that the expressions of the human face were a gateway to the soul of man. Unlike Lavater and other physiognomists of the era, Duchenne was skeptical of the face’s ability to express moral character; rather he was convinced that it was through a reading of the expressions alone (known as pathognomy) which could reveal an “accurate rendering of the soul’s emotions”