which the resounding tubes are tuned, those notes will sound loudly and almost yell in our ears; while if the tubes do not correspond to the harmonics of the note played, the resounding tubes will not answer in the same manner. We thus see, again, that what seems to us a simple impression, the one note struck on the pianoforte, consists of many impressions which together make up what we hear and perceive. We are not conscious of the harmonics which follow each note and determine its quality, but we know, nevertheless, that these by-notes strike our ear, and that our senses receive them and suffer from them. The same remark applies to the whole realm of our sensuous knowledge. There is a broad distinction between sensation and perception. There are many things which we perceive at first and which we perceive again as soon as our attention is called to them, but which, in the ordinary run of life, are to us as if they did not exist at all. When I first came to Oxford, I was constantly distracted by the ringing of bells; after a time I ceased even to notice the dinner-bell. There are earrings much in fashion just now-little gold bells with coral clappers. Of course they produce a constant jingling which everybody hears except the lady who wears them in her ears. In these cases, however, the difference between sensation and perception is simply due to want of attention. In other cases our senses are really incapable, without assistance, of distinguishing the various constituents of the objective impressions produced from without. We know, for instance, that white light is a vibration of ether, and that it is a compound of the single colours of the solar spectrum. A prism will at once analyse that compound, and divide it into its component parts. To our apprehension, however, white light is something simple, and our senses are too coarse to distinguish its component elements by any effort whatsoever. We now shall be better able to understand what I consider a most important discovery of Professor Helmholtz.13 It had been proved by Professor G. S. Ohm' that there is only one vibration without harmonics, viz. the simple pendulous vibration. It had likewise been proved by Fourier, Ohm, and other mathematicians, 15 that all compound vibrations or sounds can be divided into so many simple or pendulous vibrations. But it is due to Professor Helmholtz that we can now determine the exact configuration of many compound vibrations, and determine the presence and absence of the harmonics which, as we saw, caused the difference in the quality, or colour, or timbre of sound. Thus he found that in the violin, as compared with the guitar or pianoforte, the primary note is strong, the secondary tones from two to six are weak, while those from seven to ten are much more distinct.16 In the clarionet" the odd harmonics only are perceptible, in the hautboy the even harmonics are of equal strength. Let us now see how all this tells on language. When we are speaking we are in reality playing on a musical instrument, and a more perfect instrument than was ever invented by man. It is a wind-in 13 Helmholtz, l. c. p..82. 15 l. c. p. 54. 17 l. c. p. 162. 14 l. c. p. 38. strument, in which the vibrating apparatus is sup plied by the chorda vocales, while the outer tube, or bells, through which the waves of sound pass, are furnished by the different configurations of the mouth. I shall try, as well as I can, to describe to you, with the help of some diagrams, the general structure of this instrument, though in doing so I can only retail the scant information which I gathered myself from our excellent Professor of Physiology at Oxford, Dr. Rolleston. He kindly showed and explained to me by actual dissection, and with the aid of the newlyinvented laryngoscope 18 (a small looking-glass, which enables the observer to see as far as the bifurcation of the windpipe and the bronchial tubes), the bones, the cartilages, the ligaments and muscles, which together form that extraordinary instrument on which we play our words and thoughts. Some parts of it are extremely complicated, and I would not venture to act even as interpreter of the dif ferent and sometimes contradictory views held by Müller, Brücke, Czermak, Funke, and other distinguished physiologists, on the mechanism of the various cartilages, the thyroid, cricoid, and arytenoid, which together constitute the levers of the larynx. It fortunately happens that the most important organs which are engaged in the formation of letters lie above the larynx, and are so simple in their structure, and so open to constant inspection and examination, that, with the diagrams placed before you, there will be little difficulty, I hope, in explaining their respective functions. 15 Czermak, Üher den Kehlkopfspiegel und seine Verwerthung. Leipzig, 1860; 2nd ed. 1863. |