datum is withheld, namely, the visibleness of the organ itself. Therefore, by sight, we can form no judgment at all with respect to the distance at which objects may be placed from the organ; or perhaps it would be more proper to say, that we do form an obscure judgment, to the effect that all visible objects lie within the sphere of the eye; and that where the object is, there also is the organ which apprehends it. Or, to repeat the proof in somewhat different words, we affirm, that before sight can judge of the distance of objects from itself, or that they are distant at all, it must first localise both itself and the object. But it can only localise these two by seeing them, for sight can do nothing except by seeing. But it cannot see both of them; it can only see one of them. Therefore, it cannot localise both of them, and hence the conclusion is driven irresistibly home, that it can form no judgment that they are in any degree distant from one another.
Touching this point Mr Bailey puts forth an averment, which really makes us blush for the speculative capacity of our country. Speaking of the case of the young man who was couched by Cheselden, he remarks, in support of his own doctrine, that visible objects are seen to be external to the sight; and in commenting on the young man's statement, that "he thought all objects whatever touched his eyes as what he felt did his skin," he remarks, we say, upon this, that it clearly proves "visible objects appeared external even to his body, to say nothing of
