112 THI] POPULAR SCIENCE MONTHLY. 



was found to begin about an inch below the breastbone, and from 

 thence to extend for about two inches downward and about the same 

 distance right and left from the middle line, while the navel, breast- 

 bone, ribs, etc., were quite insensitive. Heidenhain seeks though not, 

 we think, very successfully to explain this curious distribution of 

 areas sensitive to sound, by considerations as to the distribution of the 

 vagus nerve. 



Next we have a chapter on the subjection of the intellectual fac- 

 ulties to the will of the operator which is manifested by j^ersons when 

 in a state of hypnotism. For the manifestation of these phenomena 

 the sleep must be less profound than that which is required for jjro- 

 ducing imitative movements ; in this stage of hypnotism the experi- 

 m.enter has not only the motor mechanism on which to operate, but 

 likewise the imagination. "Artificial hallucinations" may be pro- 

 duced to any extent by rehearsing to the patient the scenes or events 

 which it may be desired to make him imagine. A number of interest- 

 ing details of particular cases are given, but we have only space to re- 

 peat one of the most curious. A medical student, when hypnotized in 

 the morning, had a long and consecutive dream, in which he imagined 

 that he had gone to ' the Zoological Gardens, that a lion had broken 

 loose, that he was greatly terrified, etc. On the evening of the same 

 day he was again hypnotized, and again had exactly the same dream. 

 Lastly, at night, while sleejiing normally, the dream was a third time 

 repeated. 



A number of experiments proved that stimulation of certain parts 

 of the skin of hypnotized persons is followed by certain reflex move- 

 ments. For instance, when the skin of the neck between the fourth 

 and seventh cervical vertebrae is gently stroked with the finger, the 

 patient emits a peculiar sighing sound. The similarity of these reflex 

 movements to those which occur in the well-known " croak-experiment " 

 of Goltz is pointed out. 



A number of other experiments proved that unilateral hypnotism 

 might be induced by gently and repeatedly stroking one side or other 

 of the head and forehead. The resulting hypnotism manifested itself 

 on the side opposite to that which was stroked, and affected both the 

 face and limbs. When the left side of the head was stroked, there 

 further resulted all the phenomena of aphasia, which was not the case 

 when the right side of the head was stroked. When both sides of the 

 head were stroked, all the limbs were rendered cataleptic, but aphasia 

 did not result. On placing the arms in Mosso's apparatus for measur- 

 ing the volume of blood, it was found that, when one arm was hypno- 

 tized by the unilateral method, its volume of blood v^as much dimin- 

 ished, while that of the other arm was increased, and that the balance 

 was restored as soon as the cataleptic condition passed off. In these 

 experiments consciousness remained unaffected, and there Avere no dis- 

 agreeable sensations experienced by the patient. In some instances. 



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