790 OF THE FUNCTIONS OF THE NERVOUS SYSTEM. 



powerful interest tends to draw off the attention elsewhere, and the thoughts 

 are found to wander continually from the subject in hand ; or when, from the 

 undue protraction of mental exertion, the state of the brain is such that the 

 thoughts no longer develop themselves consecutively in the mind, nor shape 

 themselves into appropriate forms of expression. In either of these cases, the 

 intellectual powers can only be kept in action upon the pre-determined subject, 

 by a strong effort of the Will ; of this effort we are conscious at the time, and 

 feel that we need to put forth even a greater power than that which would be 

 required to generate a large amount of physical force through the muscular 

 system ; and we subsequently experience the results of it, in the feeling of 

 excessive fatigue which always follows any exertion that calls the Cerebrum 

 into extraordinary activity. 



818. But we seem justified in proceeding further, and in affirming that the 

 Cerebrum may act upon impressions transmitted to it, and may elaborate results 

 such as we might have attained by the purposive direction of our minds to the 

 subject, without any consciousness on our own parts; so that we only become 

 aware of the operation which has taken place, when we compare the result, as 

 it presents itself to our minds after it has been attained, with the materials 

 submitted to the process. The ordinary experience of most persons will supply 

 them with examples of this form of Cerebral activity. One of the simplest in- 

 stances of it is to be found in the process by which we acquire a knowledge of 

 the meaning of an author whose writings we are perusing. For, if the subject 

 be one into which we readily enter, and if the writer's flow of thought be one 

 which we easily follow, and his language be appropriate to express his ideas, we 

 acquire the meaning of one sentence after another, without any conscious 

 recognition of the meaning of each of the component words; and yet it is cer- 

 tain that a particular impression must have been made by each of these words 

 upon the Cerebrum, before we can comprehend the notion which they were 

 collectively intended to convey. It is only when the language is ill chosen, or 

 when we do not readily follow the author's train of thought, that we direct our 

 attention to the signification of the individual words, and become conscious of 

 their separate meaning. In like manner, an expert calculator will cast his eye 

 rapidly from the bottom to the top of a column of figures and will name the 

 total, without any conscious appreciation of the value of each individual figure. 

 But in these instances, no higher act of mind is required than the production 

 of one complex idea out of an aggregate of simpler elements; there are cases, 



production of those works which have rendered his name immortal, it was enough for him 

 once to fix his thoughts in the first instance upon the subject (the libretto of an opera, for 

 example, or the words of a religious service), so as to give the requisite start and direction 

 to his ideas, which then flowed onwards without any eifort of his own ; so that the whole 

 of a symphony or an overture would develop itself in his mind, its separate instrumental 

 parts taking (so to speak) their respective shapes, without any intentional elaboration. In 

 fact, the only exercise of Will that seemed to be required on his part consisted in the not- 

 ing down of the composition when complete ; and this, under the temptations of social 

 intercourse, and a dislike to anything like " work," he would sometimes postpone until the 

 last moment. Thus it is well known that his overture to Don Giovanni was only written 

 out (although it must have been previously composed) during the night previous to its 

 performance, which took place without any rehearsal. It is recorded of him, that being 

 once asked by an inferior musician how he set to work to compose a symphony, he replied 

 " If you once think of how you are to do it, you will never write anything worth hearing. / 

 write because I cannot help it." Mozart, like Coleridge, was a man of extremely weak 

 will ; he could neither keep firm to a resolution, nor resist temptation ; and when not under 

 the guidance of his excellent wife, was the sport of almost every kind of impulse. But 

 there was probably never a more remarkable example than his musical career presents, of 

 the automatic operation of that creative power which specially constitutes Genius ; and his 

 life is altogether a most interesting study to the Psychologist, as well as to the Musician. 

 (See especially the "Life of Mozart" by Edward Holmes.) 



