668 THE POPULAR SCIENCE MONTHLY. 



conscience. They are content to rest in the uncertain position which 

 satisfied Dr. Abercrombie, the distinguished author of the well-known 

 " Inquiry concerning the Intellectual Powers," who, having pointed 

 out plainly the dependence of mental function on organization, and, as 

 a matter of fact which can not be denied, that there are individuals in 

 whom every correct feeling in regard to moral relations is obliterated, 

 while the judgment is unimpaired in all other relations, stops there 

 without attempting to prosecute inquiry into the cause of the remark- 

 able fact which he justly emphasizes. " That this power," he says, 

 " should so completely lose its sway, while reason remains unimpaired, 

 is a point in the moral constitution of man which it does not belong 

 to the physician to investigate. The fact is unquestionable ; the solu- 

 tion is to be sought in the records of eternal truth." And with this 

 lame and somewhat melancholy conclusion he leaves his readers im- 

 potent before a problem which is not only of deep scientific interest, 

 but of momentous practical importance. The observation which makes 

 plain the fact does not, however, leave us entirely without information 

 concerning the cause of it, when we pursue it faithfully, since, it re- 

 veals as distinct a dependence of moral faculty upon organization as 

 of any other faculty. 



Many instructive examples of the pervading mental effects of 

 physical injury of the brain might be quoted, but two or three, re- 

 cently recorded, will suffice. An American medical man was called 

 one day to see a youth, aged eighteen, who had been struck down 

 insensible by the kick of a horse. There was a depressed fracture of 

 the skull a little above the left temple. The skull was trephined, and 

 the loose fragments of bone that pressed upon the brain were removed, 

 whereupon the patient came to his senses. The doctor thought it a 

 good opportunity to make an experiment, as there was a hole in the 

 skull through which he could easily make pressure upon the brain. 

 He asked the boy a question, and before there was time to answer it 

 he pressed firmly with his finger upon the exposed brain. As long as 

 the pressure was kept up the boy was mute, but the instant it was re- 

 moved he made a reply, never suspecting that he had not answered at 

 once. The experiment was repeated several times with precisely the 

 same result, the boy's thoughts being stopped and started again on 

 each occasion as easily and certainly as the engineer stops and starts 

 his locomotive. 



On another occasion the same doctor was called to see a groom 

 who had been kicked on the head by a mare called Dolly, and whom 

 he found quite insensible. There was a fracture of the skull, with 

 depression of bone at the upper part of the forehead. As soon as the 

 portion of bone which was pressing upon the brain was removed the 

 patient called out with great energy, " Whoa, Dolly ! " and then 

 stared about him in blank amazement, asking : ""Where is the mare? 

 Where am I ? " Three hours had passed since the accident, during 



