The weight of the brain in insane persons has been investigated by Dr. Parchappe in France, Dr. Bergmann in Germany, and on a larger scale, by Dr. Boyd in this country.∗ Further observations, however, were, for many reasons, to be desired; and having during many years past either weighed myself, or caused to be weighed, the brain of nearly every patient who has died whilst under my care, I ventured to think the large series of observations thus obtained, and which amount to 470 cases, were worthy of being collected, analysed, and compared with the weights recorded by previous observers.