268 Dr. E. Yung on the Errors 



On the other hand, if it is not specified, they always do it 

 themselves with a remarkable abundance of details, as we have 

 already seen. T have tested this upon 28 persons of both 

 sexes, nineteen of whom, women especially, declared that they 

 perceived a certain odour upon the piece of money which they 

 pointed out, and which had not been specially touched, just 

 as in the experiment of the card. 



One young man said that "it seemed" to him that the 

 piece which he had just picked out diffused a "sharp, dry" 

 odour ; the second time he recognized this odour more deci- 

 dedly and became very positive. A lady refused to repeat 

 the experiment because the odour affected her heart, &c. 



On one single occasion I excited at the same time the hal- 

 lucination of a shock and of an odour, by having the piece 

 simultaneously touched and smelt. 



Here then we have a certain number of facts which demon- 

 strate how easy it is to induce hallucinations, of vision, of 

 touch, and of smell in persons who are not subject to any 

 thing of the kind, who are in good health, perfectly awake, 

 and appear to be very far from those neurotic conditions to 

 which we shall recur, and which predispose to all the falsifica- 

 tions of sensibility. 



As regards hallucinations of hearing I have obtained only a 

 very small number of results, because the arrangements which 

 have just been described are not favourable to their excite- 

 ment. Nevertheless four persons, prepared in an analogous 

 manner to that described, distinctly heard one of the cards of 

 the figure close to which they placed an ear " diffuse a sort of 

 buzzing sound." Hallucinations of hearing, indeed, are not 

 difficult to excite in a silent medium. In the evening I have 

 often caused people to hear the horn announcing a fire by 

 asserting that I heard it myself; and in a party, if one affirms 

 that one hears the bells ring, one always meets with some 

 persons who assert that they hear them ring also. 



It is to be remarked that in all the cases which have just 

 been under consideration, the persuasion of the reality of the 

 sensation is such that it is very difficult to demonstrate to the 

 person that this reality does not exist. It is of no use to tell 

 him that you have deceived him; he is too certain of having ex- 

 perienced the sensation to be willing to agree to it. A lady 

 told me " that she would put her hand in the fire " rather than 

 believe that there was any mistake. The history of the sciences 

 takes cognizance of examples of philosophers who, after having 

 thought that they observed such or such a phenomenon of nature 

 to support a favourite theory, have never been willing to recog- 

 nize that they have deceived themselves. This is an imperfec- 



