ON SENSORIAL VISION. 



patterns, but not clearly enough to make them well out. 

 On both these occasions the patterns were far more 

 lively and conspicuous than the dim and shadowy forms 

 before spoken of, and probably belong to quite a differ- 

 ent class of phenomena. 



(13.) Since that time circular forms have presented them- 

 selves spontaneously, of the shadowy and obscure class, 

 on three occasions, one of them quite recently. On the 

 first of these, circular were combined with straight lines 

 forming a series of semicircular arches, supported by, or 

 rather prolonged beneath into, tall slender vertical 

 columns, the whole like small wirework ; mere lines, 

 and bright on a dark ground ; while another series of 

 similar arches and uprights darker than the general 

 ground appeared, intersecting the former so as to have 

 the dark uprights just intermediate between the bright 

 ones of the first set. On the second occasion the pattern 

 consisted of a very slender and delicate circular hoop, 

 surrounded with a set of other circles of the same size, 

 exterior tangents to the central circle and to each other. 

 On the third, the whole visual area was covered with 

 separate circles, each having within it a four-sided 

 pattern of concave circular arcs. All these phenomena 

 were, however, much fainter than the chloroform exhibi- 

 tions, and of the order of the lattice patterns. 



(14.) Now the question at once presents itself- What 

 are these Geometrical Spectra ? and how, and in what 

 department of the bodily or mental economy do they 

 originate? They are evidently not dreams. The mind 

 is not dormant, but active and conscious of the direction 



