IV. 



ON THE INFLUENCE OF SUGGESTION IN MODIFY- 

 ING AND DIRECTING MUSCULAR MOVEMENT, 

 INDEPENDENTLY OF VOLITION. 



[From a report of a Lecture at the Royal Institution, March 12, 1852.] 



It now remains to inquire whether any such physiological ac- 

 count can be given of the "biological" state, as shall enable us 

 to refer it to any of the admitted laws of action of the nervous 

 system. This, the lecturer stated, was the point which he was 

 the most desirous of elucidating ; and in order to prepare his 

 auditors for the reception of his views, he gave a brief explanation 

 of those phenomena of "reflex" action (now universally recog- 

 nized by physiologists), in which impressions made upon the 

 nervous system are followed by respondent automatic movements. 

 Such movements have hitherto been distinguished into the excito- 

 motor, which are performed, without the exciting impression being 

 necessarily felt, through the instrumentality of the spinal cord and 

 the nerves connected with it ; and the scnsori-motor, in which sensa- 

 tion necessarily participates, the respondent motions not being 

 executed unless the impressions are felt, and their instrument 

 being the chain of sensory ganglia (collectively constituting the 

 " sensorium ") which lies between the spinal cord and the cere- 

 brum, and is intimately connected with both. The automatic 

 movements of breathing and swallowing, which continue during 

 a state of profound insensibility, are examples of the former 

 group ; whilst the start upon a loud sound, the closure of the 

 lids to a flash of light, or the sneezing induced by the dazzling 

 of the eyes, as well as by the irritation of the nasal passages, are 

 instances of the latter. The whole class of purely emoiional 

 movements may be likened to these ; for in so far as they are 



