142 



PSYCHOLOGT. 



In the eye, intensity of nerve-stimulation seems to in- 

 crease the volume of the feeling as well 

 as its brilliancy. If we raise and lower 

 the gas alternately, the whole room and 

 all the objects in it seem alternately to 

 enlarge and contract. If we cover half 

 a page of small print with a gray glass, the 

 print seen through the glass appears 

 decidedly smaller than that seen outside 

 of it, and the darker the glass the greater 

 the difference. When a circumscribed 

 oj)acity in front of the retina keeps off 

 part of the light from the portion which 

 it covers, objects projected on that 

 portion may seem but half as large as 

 when their image falls outside of it.* 

 The inverse effect seems produced by 

 certain drugs and anesthetics. Mor- 

 phine, atropine, daturine, and cold blunt 

 the sensibility of the skin, so that dis- 

 tances upon it seem less. Haschish pro- 

 duces strange perversions of the general 

 sensibility. Under its influence one's 

 body may seem either enormously en- 

 larged or strangely contracted. Some- 

 times a single member will alter its 

 proportion to the rest ; or one's back, 

 for instance, will appear entirely absent, 

 as if one were hollow behind. Objects 

 comparatively near will recede to a vast 

 distance, a short street assume to the 

 eye an immeasurable perspective. Ether and chloroform 



b c a 



Fig. 52 (after Weber). 



«extreme points, with the interval between them unexcited, this interval will 

 aeem considerably less in the second case than it seemed in the first. In 

 the skin the unexcited interval feels the larger. The reader may easily 

 verify the facts in this case by taking a visiting-card, cutting one edge of 

 it iato a saw-tooth pattern, and from the opposite edge cutting out all but 

 the two corners, and then comparing the feelings aroused by the tvv'o edges 

 when held against the skin. 



* Classen, Physiologic des Gesichtssinnes, p. 114 ; see also A. Riehl, Der 

 Philosophische Kriticismus, ii. p. 149. 



