In vulgar discourse, the object of our Sense of Hearing is a sounding body. We say that we hear the bell, the trumpet, the cannon. This language, however, is not correct. That which precedes the feeling received through the ear, is the approach of vibrating air to the ear. Certain bodies, made to vibrate in a certain way, communicate vibrations to the air, and the vibrating air, admitted into the ear, is followed by the sensation of hearing. If the air which the body makes to vibrate does not enter the ear, however the body itself may vibrate, sensation does not follow; hearing does not take place. There is, in fact, no sound. Of the circumstances in which sound is generated, part only were present. There was the organ, and there was the object, but not that juxta-position which is needed to make the antecedent of the sensation complete. Air vibrating in juxta-position to the organ, is the object of Hearing. How air in vibration should produce the {17} remarkable effect, called hearing, in the nerves of the ear, and no effect in those of the eye, in those of smelling, or those of taste, our knowledge does not enable us to tell. It is not very difficult to think of the sensation of hearing, apart from the organ, and from the object, as well as from every other feeling. I hear the hum of bees. The feeling to which I give this name is a point of my own consciousness; it is an elementary part of my sensitive being; of that thread of consciousness, drawn out in succession, which I call myself. I have the hearing; it is a sensation of my own; it is my feeling, and no other man's feeling; it is a very different feeling from taste, and a very different feeling from smell, and from all my other feelings. I hear the song of birds, I hear the lowing of oxen, I hear the sighing of the wind, I hear the roaring of the sea. I have a feeling, in each of these cases; a consciousness, which I can distinguish not only from the feelings of my other senses, but from the other feelings of the same sense. If I am asked, what takes place in me, when a trumpet is unexpectedly sounded in the next room, I answer, a sensation, a particular feeling. I become conscious in a particular way. The number of those feelings which we are able to distinguish is very great. In this respect, the organ of hearing in man, is much more perfect than the organ of smell. The organ of hearing can distinguish, not only the voices of different classes, but of different individuals in the same class. There never, probably, {18} was a man whose voice was not distinguishable from that of every other man, by those who were familiarly acquainted with it. The most simple case of sound is that perhaps of a single note on a musical instrument. This note may be sounded on an endless number of instruments, and by an endless number of human voices, from no two of which will the same sound exactly be returned.