206 STRUCTURE OF THE BRAIN. 



commenced, medicine may come armed with its 

 most powerful remedies, and directed by the most 

 consummate skill, but it will too often come in vain, 

 for the patient will be no longer within its reach. 



CHAPTER VIII. 



Nervous System Structure of the Brain Its Functions 

 Connexion between the Mind and Brain Conditions of 

 Health in the Brain Hereditary Predisposition Influence 

 of the Blood on the Brain Influence of Exercise on the 

 Brain Effects of insufficient Exercise Effects of excessive 

 Exercise at different Ages Case of Sir H. Davy Rules for 

 the proper Exercise of the Brain Best Time for Mental 

 Exertion Regularity essential Repetition Every Mental 

 Power to be exercised directly on its own Objects Illustra- 

 tions Influence of the Nervous System on the general 

 Health Examples. 



IN man and the higher order of animals, the ner- 

 vous system is composed of, 1st, the brain ; 2d, the 

 spinal marrow ; and, 3d, the nerves. But, on the 

 present occasion, it will be necessary to confine our 

 remarks chiefly to the brain ; and, even regarding 

 it, to offer observations only on such points as all 

 are agreed upon, and the general reader can easily 

 comprehend. 



The brain is that large organized mass which, 

 along with its enveloping membranes, completely 

 fills the cavity of the scull. It is the seat of thought, 

 of feeling, and of consciousness, and the centre to- 

 wards which all impressions made on the nerves 

 distributed through the body are conveyed, and from 

 which the commands of the will are transmitted to 

 put the various parts in motion. 



The structure of the brain is so complicated, that- 

 less is known of its true nature than of that of almost 



