158 THE POPULAR SCIENCE MONTHLY. 



the world is its annihilation, and it is toward this term of all evils that 

 the supreme intelligence is leading us. 



To establish the truth of this doctrine, Hartmann has elaborated 

 his theory of the unconscious. Is it science? or is it really nothing 

 else than a metaphysical romance ? It is this that we propose in the 

 next part to investigate. 







HOW THE FEELINGS AFFECT THE HAIE. 



By DANIEL H. TUKE, M. D. 



THE influence of grief or fright in blanching the hair has been 

 generally recognized. 



" For deadly fear can Time outgo, 



And blanch at once the hair." Maemion. 



It has been a popular rather than a physiological belief that this 

 can occur "in a single night." No one doubts that the hair may turn 

 gray, gradually, from moral causes, and this is sufficient proof of the 

 mind's influence upon the nutrition of the hair. I have known alter- 

 nations in the color of the hair (brown and gray) corresponding to 

 alternations of sanity and insanity. Some entertain doubts as to sud- 

 den blanching of the hair, but I do not believe them well founded, and 

 can vouch for the truth of the following interesting; cases 



"Thomas W., about twenty years of age, the son of a milkman, was tall, 

 fleshy, good looking, slightly bronzed, hair intensely black, stiff, wiry, and rather 

 inclined to curl. His general appearance was that of a healthy and well-formed 

 man, used to light work, but much exposure in the open air. In the year 18 

 one of his thoughtless companions told him (what was not true) that a girl in 

 the town was going before the magistrate on the morrow to swear him father 

 of her child. Poor W. was dumfounded. The announcement had given his 

 whole frame a severe shock; the gall of bitterness had entered his heart, and 

 the mind was under the baneful influence of its power. He hastened home, and 

 sought relief in his bedroom. Sleep was denied him, for his brain was on fire. 

 He saw nothing but disgrace coming from every angle of the room. Such was 

 the mental agitation produced by a silly trick. Early morning brought no re- 

 lief ; he looked careworn, distressed, and his hair was changed from its natural 

 tint to that of a light ' iron-gray color.' This, to him, was a great mystery. In 

 the course of the following day the stupid trick was explained, but the ill effects 

 of it lasted for a long period. Nearly twenty years after, although his health 

 was fair, the mental powers retained signs of the severe shock they had re- 

 ceived; his hair was perfectly gray, and a medical friend of mine who met him 

 received the impression that he would carry the marks of this folly to his 

 grave. 



" I know of a captain of a vessel, under forty years of age, who suffered ship- 

 wreck twice. On the first occasion (in which he lost all hope) his hair quickly 

 turned gray; and on the second, some considerable time afterward, his hair be- 



