THE INFLUENCE OF A MAGNET 63 



long as the bar of iron was not magnetised she shrunk 

 from a pin-prick applied to the same part. I saw this 

 experiment with Charcot and some others present, and 

 I noticed that the order to an assistant to "make 

 contact," that is to say, to convert the bar of iron into 

 a magnet, was given very emphatically by Charcot, and 

 that there was an attitude of expectation on the part of 

 all present which was followed by the demonstration 

 by means of needle-pricking that the young woman's 

 arm had lost sensation, or, as they say, " was in a state 

 of anaesthesia." 



Charcot went away saying he should repeat the ex- 

 periment before some medical friends in an hour or two. 

 In the meantime, being left alone in the laboratory 

 with my companion as witness, I emptied the chemical 

 fluid (potassium bichromate) from the electric battery 

 and substituted pure water. It was now incapable of 

 setting up an electric current and converting the bar 

 into a magnet. When Charcot returned with his 

 visitors, the patient was brought in, and the whole 

 ritual repeated. There was no effect on sensation when 

 the bar was held in the hand so long as the order to 

 set the current going, and so magnetise the bar, had 

 not been given. At last the word was given, " Make ! " 

 and at once the patient's arm became anaesthetised, as 

 earlier in the day. We ran large carpet-needles into 

 the hand without the smallest evidence of the patient's 

 knowledge. The order was given to break the current 

 (that is, to cease magnetising the bar), and at once the 

 young woman exhibited signs of discomfort, and 

 remonstrated with Charcot for allowing such big needles 

 to be thrust into her hand when she was devoid of 

 sensation ! My experiment had succeeded perfectly. 



It would not have done to let Charcot, or anyone 

 else (except my witness) know that when the order 

 " Make v was given, there was no " making," but that 

 the bar remained as before un-magnetised. The con- 



