Physiognomy is a pseudoscientific discipline that purports to find correspondences
between psychological attributes and physical features of the head, face, and body.
Victor has every reason to use the term, since his medieval mentor Albertus Magnus
wrote extensively about physiognomy and the mixture of humors in the body and mind.
As Mary Shelley would have been well aware, this discipline was resurrected in the
later eighteenth century by a countryman of Victor Frankenstein's, Johann Kaspar Lavater
(11 November 1741 - 2 January 1801), a resident of Zurich. His Essays on Physiognomy
(1775-1778; translated into English in 1789-1798) made him world-famous, inspiring
many a quack psychologist of his day, and many further days across the ensuing century.
More seriously relevant for the context of Frankenstein might be the title of an earlier
work of Lavater's, Geheimes Tagebuch von einem Beobachter seiner selbst (1772-73),
which was translated into English in 1795 under the title Secret Journal of a Self-Observer.
Compare I:2:12 and note and I:6:41 and note.