VISUAL IMAGES IN DARKNESS. 735 



sented is that of lattice-work, the longer axis of the rhombs being ver- 

 tical. Sometimes, however, the larger axes are horizontal. The lines 

 are sometimes dark on a light ground, and sometimes the reverse. 

 Occasionally at their intersection appears a small, close, and apparently 

 complete piece of pattern work, but always too indistinct to be clearly 

 made out. 



" Occasionally the latticed pattern is replaced by a rectangular 

 one, and within the rectangles occurs in some cases a filling-up of a 

 smaller lattice-pattern or of a lozenge of filigree-work, of which it is 

 impossible to seize the precise form, but which is evidently the same 

 in all the rectangles. 



" Occasionally, too, but much more rarely, complex and colored 

 patterns like those of a carpet appear, but not of any carpet distinctly 

 remembered or lately seen ; and in two or three instances in which 

 this has been the case the pattern has not remained constant, but has 

 kept changing from instant to instant, hardly giving time to appre- 

 hend its symmetry and regularity, before being replaced by another ; 

 that other, however, not being a sudden transition to something totally 

 different, but rather a variation on the former." 



Thus far I have spoken of rectilinear forms ; with myself, however, 

 curvilinear forms more frequently present themselves. These so close- 

 ly resemble the spectra which Sir John describes as having presented 

 themselves to him when under anaesthetic influence, that I again quote 

 his words : 



" The indication," he says, " by which I knew it " (the chloroform) 

 " had taken effect consisted of a kind of dazzles, immediately followed 

 by the appearance of a very beautiful and perfectly symmetrical 

 Turk's-cap pattern formed by the intersection of a great many circles 

 outside and tangent to a central one. It lasted long enough for me to 

 contemplate it so as to seize the full impression of its perfect regu- 

 larity, and to be aware of its consisting of exceedingly delicate lines, 

 which seemed, however, to be not single but close assemblages of col- 

 ored lines not unlike the delicate fringes formed along the shadows of 

 objects by minute pencils of light. The whole exhibition lasted, so far 

 as I could judge, hardly more than a few seconds." 



On the administration of chloroform a second time, after an inter- 

 val of many months, " the Turk's-cap pattern again presented itself on 

 the first impression, which I watched with some curiosity ; but it was 

 not quite so complete as, nor was it identical with the former. In the 

 intersections of the circles with each other I could perceive small loz- 

 enge-shaped forms or minute patterns, but not clearly enough to make 

 them well out. On both these occasions the colors were lively and 

 conspicuous. . . . Since that time circular forms have presented them- 

 selves, spontaneously, of the shadowy and obscure class. On one occa- 

 sion circular were combined with straight lines, forming a series of 

 semicircular arches, supported by, or, rather, prolonged beneath into, 



