made, and beautifully adjusted the external organs of sense, one to another, and each to all, that when one is lacking the others are made able, by greater exercise, to perform the functions of the missing one.  For example, if one loses his hearing, sight is rendered keener, and the nerves acquire a sensitiveness almost painful.  Dr. Kitto, who was deaf from twelve years of age, speaks of this peculiar sensitiveness as follows:  “The drawing of furniture, as tables or chairs, over the floor, above or below me, the shutting of doors, and the feet of children at play, distress me far more than the same cause would do if I were in actual possession of my hearing.

“By being unattended by any circumstances or preliminaries, they startle dreadfully; and by the vibration being diffused from the feet over the whole body, they shake the whole nervous system in a way which even long use has not enabled me to bear.”

In the same interesting article on percussion, he says:  “A few days since, when I was seated with the back of my chair facing a chiffonier, the door of this receptacle was opened by some one, and swung back so as to touch my hair.  The touch could not but have been slight, but to me the concussion was dreadful, and almost made me scream with the surprise and pain; the sensation being very similar to that which a heavy person feels on touching the ground, when he has jumped from a higher place than he ought.  Even this concussion, to me so violent and distressing, had not been noticed by any one in the room but myself.”

This physiological phenomenon is analagous to the sensation experienced by the blind on approaching any tall or broad object.  We feel their presence when we are several yards from them.  I have sometimes been startled by the sudden impression produced by a lamp-post, or tree when in fact it was a yard or more from me.  The sensation is somewhat like receiving a smart blow in the face.  I am frequently aware of passing a building while riding along a country road, and the proximity of trees, fences and other objects is quite perceptible.

This is not a latent sense, developed by circumstances, as some have supposed, but a wonderful acuteness of the nerves of the face, and more particularly of the nerves of the eye-lids.  These phenomena may, I think, be explained in this way.  When one of the superior senses is absent, the perceptive force that has watched at the eye, or listened at the ear, is now transferred to other nerves of sensation.  In other words, a deaf person is all eyes, and extremely alive to tangible percussions, as will be seen in the case of Dr. Kitto and others.  The blind are all ears and fingers, and certain of the inferior animals are all ears and heels; I am not sure but there is some neck in both cases.  Since it has been shown that new perceptions and conditions have been developed in the absence of one or more of the superior senses, that the deaf are so keenly cognizant