injured, and the slightest injury perilling life, a free and secure place to act in. The fragile part of the apparatus is defended by the osseous portion of it, the play of the latter being equally essential to the function as that of the former. In like manner the tender and delicate substance of the brain and spinal cord, the central seat of the animal life, with which all the senses are in intimate communion, is protected by bones and muscles which perform important voluntary movements while the organs of sense which put us in connexion with the external world, which render us susceptible of pleasure, and which give us notice of the approach of objects capable of exciting pain, are placed where external bodies may be brought most conveniently and completely into contact with them; and where alone they can be efficient as the sentinels of the system. For this reason, with the exception of the sense of touch, which, though placed especially at the extremities of the fingers, is also diffused over the whole external surface of the frame, all the senses have their several seats in the head, the most elevated part of the body, of an ovoid figure, capable of moving independently of the rest of the fabric, and which, being supported on a pivot, is enabled to describe at least two-thirds of a circle. Such is the difference in the structure and position of the apparatus of the two lives, but the difference in their action is still more striking. 1. The action of the apparatus of the organic life when sound is without consciousness; the object of the action of the apparatus of the animal life is the production of consciousness. The final cause of the action of the apparatus of the organic life is the maintenance of existence; the final cause of the action of the apparatus of the animal life is the production of conscious existence. What purpose would be answered by connecting consciousness with the action of the organic organs? Were we sensible of the organic processes; did we know when the heart beats, and the lung plays, and the stomach digests, and the excretory organ excretes, the consciousness could not promote, but might disturb the due and orderly course of these processes. Moreover they would so occupy and engross our minds that we should have little inclination or time to attend to other objects. Beneficently therefore are they placed equally beyond our observation and control. Nevertheless, when our consciousness of these processes may be of service; when they are going wrong; when their too feeble or too intense action is in danger of destroying existence, the animal life is made sensible of what is passing in the organic, in order that the former may take beneficial cognizance of the latter, may do what experience may have taught to be conducive to the restoration of the diseased organ to a sound state, or avoid doing what may conduce to the increase or maintenance of its morbid condition.