4 Pages in Charles Darwin's Library associated with "mental states - pleasure"

De la physionomie et des mouvements d'expression.
By: Gratiolet, Pierre.
Publication info: Paris :J. Hetzel,1865.
Pages: Page 335
Elements of physiology.
By: Müller, Johannes. - Baly, William,
Publication info: London :Taylor & Walton,1838-1842.
Volume: v.2
Pages: Page 1407 Page 1701
On the genesis of species.
By: Mivart, St. George Jackson,
Publication info: London :Macmillan & Co.,1871.
Pages: Page 196