bodies, which makes them reflect different rays of light, may make them feel as differently to the exquisite touch of a blind man. But there is so much difference in the tangible qualities of things of the same colour, so much roughness and smoothness, harshness and softness, arising from other causes, that it is more difficult to conceive how that minute degree arising from colour should be distinguished, than how a blind man should talk sensibly on the subject without having made such distinction. We cannot conceive how a piece of red velvet, woollen cloth, camblet, silk, and painted canvass, should have something in common, which can be distinguished by the touch, through the greatest difference in all qualities which the touch can discover; or in what mode green buckram should be more soft and pleasing to the touch than red velvet If the softness peculiar to green be distinguished in the buckram, and the harshness peculiar to red in the velvet, it must be by some quality with which the rest of mankind are as little acquainted as the blind with colour. It may perhaps be said, that a blind man is supposed to distinguish colours by his touch, only when all things are equal. But if this be admitted, it would as much violate the order of his ideas to call velvet red, as to call softness harsh, or, indeed, to call green red; velvet being somewhat soft and pleasing to the touch, and somewhat soft and pleasing to the touch being his idea of green."
The acuteness of these remarks leaves us to regret that the author eluded the discussion of the most difficult part of the subject, and fixed upon that concerning which there is no dispute: Blacklock himself acknowledged what is here said about distinguishing colours by the touch, to be true as far as he was concerned, that being a nicety of perception which, though reported to be possessed by others, he in vain endeavoured to attain. "We have known a person," he says, in his article on Blindness, "who lost the use of his sight at an early period of infancy, who, in the vivacity or delicacy of his sensations, was not, perhaps, inferior to any one, and who had often heard of others in his own situation capable of distinguishing colours by touch with the utmost exactness and promptitude. Stimulated, therefore, partly by curiosity, to acquire a new train of ideas, if that acquisition were possible, but still more by incredulity with respect to the facts related, he tried repeated experiments by touching the surfaces of different bodies, and examining whether any such diversities could be found in them as might enable him to distinguish colours; but no such diversity could he ever ascertain. Sometimes, indeed, he imagined that objects which had no colour, or, in other words, such as were black, were somewhat different and peculiar in their surfaces; but this experiment did not always, nor universally hold."
But even supposing Dr Blacklock to have possessed the power of distinguishing colours by the touch, and that by handling the coat which he wore he could have told whether it was blue or black, the stock of ideas that he might thereby have obtained, would have contributed little to fit him for describing external nature. He could have formed no conception of a landscape from the representation of it on canvass, which, at the most, could only convey the idea of a plain surface covered with a variety of spots, some of which were smoother and more pleasant to the touch than others. The pomp of groves and garniture of fields would never have been disclosed to his yearning fancy by so slow and imperfect a process. Nor could his notions of scenery be much improved by whatever other conventional method he endeavoured to form them. Granting that he framed his idea of the sun upon the model of that of glory, it was still but an abstract idea, and could bring him no nearer to a distinct apprehension of the splendour with which light covers the face of the earth; nor could his idea of
