How can you tell if someone is suffering from idiocy? Or perhaps has an acute case of chronic mania? Why, from their appearance, of course. Or so suggests the 1883 manual Types of Insanity: an Illustrated Guide in the Physical Diagnosis of Mental Disease, by Allan McLane Hamilton, M.D., which we recently spotted over at Retronaut. After the jump, see if you can spot yourself among the plates, and you may just come out feeling a little thankful for how far mental health treatment has come.