it is all about.  This law of habitual action applies not only to the lower nerve-centres in their healthy condition, but with equal force in disease.  It is notorious that one of the great difficulties in the cure of epilepsy is the habit which is acquired by the nerve-centres of having at intervals attacks of convulsive discharge of nerve-force.  Some years since I saw in consultation a case which well illustrates this point.  A boy was struck in the head with a brick, and dropped unconscious.  On coming to be was seized with an epileptic convulsion.  These convulsions continually recurred for many months before I saw him.  He never went two hours without them, and had usually from thirty to forty a day—­some, it is true, very slight, but others very severe.  Medicines had no influence over him, and with the idea that there might be a point of irritation in the wound itself causing the epilepsy, the scar was taken out.  The result was that the seizures were the same day reduced very much in frequency, and in a short time became amenable to treatment, so that finally complete recovery occurred.  He had, however, probably fifty convulsions in all after the removal of the scar before this result was achieved.  Undoubtedly, in this case the point of irritation was removed by the operation.  The cause of the convulsions having been taken away, they should have stopped at once.  But here the law of habitual action asserted itself, and it was necessary to overcome the remembrance of the disease by the nerve-centres.  It is plain that the higher nerve-centre remembers the idea or fact because it is impressed by ideas and facts, precisely as the lower spinal nerve-centres in the frog remember irritations and movements which have impressed them.  The faculty of memory resides in all nerve-centres:  the nature of that which is remembered depends upon the function of the individual centre.  A nerve-cell which thinks remembers thought—­a nerve-cell which causes motion remembers motion.

The so-called cases of double consciousness are perfectly simple in their explanation when the true nature of memory is borne in mind.  In these cases the subject seems to lead a double life.  The attacks usually come on suddenly.  In the first attack all memory of the past is lost.  The person is as an untaught child, and is forced to begin re-education.  In some of these cases this second education has gone on for weeks, and advanced perhaps beyond the stage of reading, when suddenly the patient passes back to his original condition, losing now all memory of events which had occurred and all the knowledge acquired in what may be called his second state, but regaining all that he had originally possessed.  Weeks or months afterward the second state reoccurs, the individual now forgetting all memory of the first or natural condition.  It is usually found that events happening and knowledge acquired during the first attack of what we have called the second state are remembered