the hinder part of the head. See Anatomy Index.

CELEBRUM, the BRAIN. Its structure and use are not so fully known as some other parts of the body; and different authors consider it in various man- ners. However, according to the observations of those most famed for their accuracy and dexterity in anato- mical inquiries, its general structure is as given in A- natomy. See Index.

Dr Hunter observes, that the principal parts of the medullary substance of the brain in idiots and mad- men, such as the thalami nervorum opticorum, and me- dulla oblongata, are found entirely changed from a me- dullary to a hard, tough, dark-coloured substance, sometimes resembling white leather.