that the taste will be irregular and confused, because one precise perception cannot succeed to two unequal, sensations which have the same object. Who does not know that substances which by some are thought perfectly insipid, afford to others a thousand subtile causes of painful or agreeable sensations?
The perfection of touch, like that of the other senses, is essentially connected to the uniformity of action of the two symmetrical halves of the body, of the two hands particularly. Let us suppose a blind man born with one hand regularly organized, while the other deprived of the antagonist motions of the thumb and fingers should form a rough, immovable surface; such a man would with great difficulty acquire notions of size, figure, direction, &c, because one identical sensation would not spring from the successive application of the two hands upon the same body. Let both touch a small sphere, for example; the one exactly embracing the extremities of all its diameters, would create the idea of rotundity; the other which could come in contact with it only at particular points, would give a very different sensation. Suspended between these two judgments, the blind man would know not which to form; he might even form a double judgment corresponding to the double sensation created by the external form of the same body as presented to the two hands. His ideas would be more correct if he condemned one hand to inaction, as he who squints turns the weakest eye from the object to avoid that confusion, the inevitable consequence of a diversity of sensations. The hands then reciprocally assist each other; the one confirms the ideas which the other has created: hence the necessary uniformity of their conformation.
The hands are not the only agents of touch ; the folds of the forearm, of the axilla, and of the groin, the concavity of the foot, &c. may furnish us with real though less per-
