Insanity is a disease at once so interesting, and so important, that it is not surprising that the subject should have been chosen by some who have preceded me in delivering the Croonian Lectures. In 1832, Dr. Seymour lectured upon the Medical Treatment of Insanity; in 1848, Dr. Conolly referred in his Lectures, more particularly to the Moral Causes and the Moral Treatment of the Disease; and in 1853, you, Mr. President, delivered your valuable Lectures on Medical Testimony and Evidence in Cases of Lunacy.