232 ON THE EFFECTS OF CERTAIN MENTAL 



duced by nitrous oxide appear to have been much exaggerated, and 

 chiefly extend to the delusions of the ear. Those from opium are 

 of a most extraordinary character ; of its effect in thus producing 

 the hallucinations of spectral forms, I have to bring forward a case 

 that perhaps has seldom been surpassed for its singularity. A meet 

 intimate friend of my own, a gentleman of high respectability, and 

 well known in the world of science, received an injury in the thumb 

 whilst abroad in a hot climate, which was followed by an attack of 

 tetanus, commonly known under the denomination of cramp or 

 locked jaw. He relied upon laudanum for his cure, and increased 

 the dose till he regularly took nine drachms every three hours night 

 and day for three weeks. He was not unusually affected by it for 

 some days, but after the lapse of a short time, the chamber in which 

 he lay appeared to extend itself on all sides till he fancied himself 

 laid in a vast library and museum. (This effect of opium in appa- 

 rently enlarging space, it will be recollected, I mentioned in my 

 second lecture.) One side of the vast dome was covered with ma- 

 rine productions of all kinds, the other fitted up with books. By 

 degrees the room became peopled with spectral forms, the living and 

 dead moved about in all the natural beauty of countenance ; the co- 

 lours of the dresses were as vivid as though they clothed breathing 

 forms ; the spectres were not transparent or filmy, but concealed 

 objects which were placed behind them, and in fact possessed all the 

 characters of living men ; they addressed him, reached down the 

 books and spread them open before him, and he has assured me that 

 many useful discoveries which he has since made were read by him 

 in the spectral books, which the no less spectral librarians reached 

 down for his perusal ; tools of all kinds were strewed over the floor, 

 the instruments of all nations, for war, agriculture, mechanics, and 

 commerce, some of which he had never before seen, but which he 

 has since recognized. This state of the imagination continued dur- 

 ing the whole time he was under the full influence of the opium: as 

 the quantity was diminished the spectres began to fade, the walls of 

 his chamber to assume their customary plain appearance, and the 

 room returned to its natural size and figure. 



Such are the chief phenomena of the Imagination in health and 

 in disease, sleeping and waking, in the sane and in the insane. 

 This extraordinary power — this great division of the faculties of the 

 mind — is the most varied in its actions, the most pleasing in its 

 effects, and the most dreadful in its unlimited workings of any of 

 the mental processes. It has been recognized in all ages as the great 

 governor and modifier of the judgment; for it will be perceived 



