i 4 2 PIONEERS OF EVOLUTION PART 



image becomes a visual image ; an imagined pain 

 a real pain, as the great physiologist, John Hunter, 

 testified when he said, 'I am confident that I can 

 fix my attention to any part until I have a sensation 

 in that part/ Shakespeare portrays the like condition 

 when Macbeth attempts to clutch the dagger where- 

 with to stab Duncan : 



1 There's no such thing ; 

 It is the bloody business which informs 

 Thus to mine eyes.' 



This abnormal state, which sees things having no 

 existence outside the ' mind's eye,' is no respecter 

 of persons ; the savage and the civilised are alike 

 its victims. It may be organic or functional. 

 Organic, when disease is present ; functional, through 

 excessive fatigue, lack of food or sleep, or derange- 

 ment of the digestive system, causing the patient, 

 as Hood says, ' to think he's pious when he's only 

 bilious.' Under such conditions, hallucinations of 

 all sorts possess the mind ; hallucinations from 

 which the true peptic, who, as Carlyle says, ' has no 

 system,' is delivered. Only the mentally anaemic, the 

 emotionally overwrought, the unbalanced, and the 

 epileptic, are the victims, whether of the lofty illu- 

 sions of august visions such as carried Saint Paul, 

 Saint Theresa, and Joan of Arc, into the presence 

 of the holiest ; or the hallucination of drowned cat, 

 thin and ' dripping with water/ born of the dis- 

 ordered nerves of Mrs. Gordon Jones. To quote 

 from Dr. Gower's Bowman Lecture (Nature, 4th July 

 1 895) on ' Subjective Visual Sensations/ such as 

 accompany fits, when, e.g., sensations of sight occur 

 without the retina being stimulated : 



