OF THE EXTERNAL SENSES. <279

Sight the Senfations of different colors, proba-bly depend upon fome difference in the nature,configuration, and arrangement of the parts whichcompofe their refpeflive furfaces. This differencemay, to a very nice and delicate touch, makefome difference in the feeling, fufficient to enablea perfon, much interefled in the cafe, to makethis diftin£lion in fome degree, though probablyin a very imperfe£t and inaccurate one. A manborn blind might poffibly be taught to make thefame diftindions. But though he might thus beable to name the different colors, which thofedifferent furfaces reflected, though he might thushave fome imperfeff notion of the remote caufesof thefe Senfations, he could have no better ideaof the Senfations themfelves, than that other blindman, mentioned by Mr. Locke, had, who faidthat he imagined the Color of Scarlet refembledthe Sound of a Trumpet. A man born deaf may,in the fame manner, be taught to fpeak articulate-ly. He is taught how to ffiape and difpofe ofhis organs, fo as to pronounce each letter, fylla-ble, and word. But Rill, though he may havefome imperfeft idea of the remote caufes of theSounds which he himfelf utters, of the remote cau-fes of the Senfations which he himfelf excites inother people; he can have none of thofe Soundsor Senfations themfelves.

If it were poffible, in the fame manner, that aman could be born without the Senfe of Touching,that of Seeing could never alone fuggeR to himthe idea of Solidity, or enable him to form any