5i6 SCIENCE PROGRESS. 



The physiological derangement, which is the basis of the 

 voHtional abeyance and o! the exalted nervous activities 

 just described, may, if hypnotism is profound, pass into a 

 more widespread derangement exhibiting itself as deep 

 hypnotic sleep. It is now associated not only with paralysis 

 of will but with profound anaesthesia, and the subject gives 

 all the physiological evidences of low^ered vitality of the 

 whole central nervous system. If the state is prolonged it 

 may become dangerous to life by lowering the activities of 

 those lower centres upon the vitality of which such essential 

 processes as respiration, etc., depend. It may, for con- 

 venience, be distinguished as the condition of lethargy and 

 resembles that produced by chloroform inhalation. 



Proposals have been actually made to employ hypnotism 

 as a method of producing anaesthesia. There are two grave 

 objections to such employment. In order to produce a pro- 

 found state of hypnotic lethargy, the subject must be made 

 extremely susceptible, and this can only be brought about 

 by repeated hypnotisation. Dr. Esdaile, who employed the 

 method in India, found it necessary to hvpnotise his patients 

 every day for several w^eeks, before he could get them into 

 a state of stupor sufficiently profound to enable him to 

 operate with safety. It is scarcely necessary to point out 

 how utterly unjustifiable such a procedure is; the state itself, 

 when reached, is more dangerous to life than that produced 

 by. ether, and far more difficult to be recovered from, whilst, 

 by the [)rocesses the subject has gone through, the patient 

 has had those physiological activities upon which his 

 volitional power depends excessively deranged and not im- 

 probably permanently enfeebled. 



The states thus described — Hypnotic Sleep, Catalepsy, 

 Somnambulism and Lethargy — are undoubtedly due to 

 an abnormal condition of the physiological activities of the 

 central nerv^ous system. In order to suggest what, in 

 accordance with modern physiology, may be presumed to 

 be the rationale of this altered condition, it is necessary 

 to sketch the essential features of normal nerve activity. 

 This is .correlated with the existence of specific structures 

 and the possession bv these of specific functional attributes. 



