3 H THE POPULAR SCIENCE MONTHLY. 



circumstances of their formation were so unusual as to keep them out 

 of ordinary associational remembrance. Thus a remarkable case is 

 mentioned by Dr. Abercombie (" Intellectual Powers," fifth edition, p. 

 149) of a boy, who, at the age of four years, underwent the operation 

 of trepanning, apparently in a state of perfect stupor, and who, after 

 his recovery, retained no recollection either of the accident by which 

 his skull was fractured, or of the operation, yet who, at the age of fif- 

 teen, during the delirium of fever, gave his mother an account of the 

 operation and of the persons who were present at it, with a correct de- 

 scription of their dress, and other minute particulars of which it was 

 scarcely possible that he could have acquired the knowledge from 

 verbal information. Here it would seem that all the Mental power the 

 patient then had must have been concentrated upon the impressions 

 made upon his Sensorium, which were thus indelibly branded (as it 

 were) upon his Organism ; but that these " traces," being soon covered 

 up by those resulting from the new experiences of restored activity, 

 remained outside the " sphere of consciousness " until revived by a 

 Physical change which reproduced the images of the objects that had 

 left them. 



The direct causal relation of Physical conditions to Mental states 

 may be made still more clear by following out into some detail the 

 phenomena of that peculiar form of Intoxication which is produced 

 by Hashish a preparation of Indian hemp used in the Levant for the 

 purpose of inducing what is termed the fantasia. The action of this 

 drug was very carefully studied some years ago by M. Moreau, Physi- 

 cian to the Bicetre, who had given great attention to the Psychology 

 of Insanity, and whose special object was to throw light upon that 

 subject by experimenting upon what he termed its artificial produc- 

 tion. His treatise, " Du Hachisch, et de 1' Alienation Mentale " (Paris, 

 1845), is one which deserves the attentive study of such as desire to 

 base their Psychology upon a comprehensive survey of facts. 



One of the first appreciable effects of the Hashish, as of other Intoxi- 

 cating agents, is the gradual weakening of that power of Volitionally 

 controlling and directing the current of thought, the possession of 

 which characterizes the vigorous mind. The individual feels himself 

 incapable of fixing his attention upon any subject ; the continuity of 

 his thoughts being continually drawn off by a succession of discon- 

 nected ideas, which force themselves (as it were) into his mind, without 

 his being able in the least to trace their origin. These speedily engross 

 his attention, and present themselves in strange combinations, so as to 

 produce the most impossible and fantastic creations. By a strong 

 effort of the Will, however, the original thread of the ideas may still 

 be recovered, and the interlopers may be driven away ; their remem- 

 brance, however, being preserved, like that of a dream recalling events 

 long since past. These lucid intervals progressively become shorter in 



