Page:Popular Science Monthly Volume 1.djvu/751

Rh is that of lattice-work, the longer axis of the rhombs being vertical. 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 apprehend 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 closely 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 regularity, and to be aware of its consisting of exceedingly delicate lines, which seemed, however, to be not single but close assemblages of colored 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 interval 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 lozenge-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 themselves, spontaneously, of the shadowy and obscure class. On one occasion circular were combined with straight lines, forming a series of semicircular arches, supported by, or, rather, prolonged beneath into,