them whithersoever they go. As far, then, as we have yet gone, it cannot be said that our vision is felt or known to be distanced from the fixed stars even by the diameter of a grain of sand. The synthesis of sight and colour is not yet discriminated. How, then, is the interval interposed? We answer, by the discovery of a tangible object in a different place from any of the tangible objects associated with colour; and then by associating, in some way or other, the operations of vision with this object. Such an object is discovered in the eye. Now, as has frequently been said, we cannot associate colours or the visual sensations with this eye; for these have been already disposed of otherwise. What, then, do we associate with it—and how? We find, upon experiment, that our apprehension of the various visual sensations depends on the presence and particular location of this small tangible body. We find that the whole array of visual phenomena disappear when it is tactually covered, that they reappear when it is reopened, and so forth. Thus we come in some way to associate vision with it—not as colour, however, not as visual sensation. We regard the organ and its dispositions merely as a general condition regulating the apprehension of the visual sensations, and no more.
Thus, by attending to the two associations that occur,—the association (in place) of visual sensations with tangible bodies that are not the eye; and the association (in place) of vision with a small tangible
