194 Transactions of the American Institute. 



decimo being present in small quantity, while the sound A was given 

 by making the second harmonical moderate in strength, the third very 

 strong, with the fourth and fifth harmonicals weak. For the produc- 

 tion of E, we have the fundamental weak, the second harmonical 

 strong, with a stronger fourth, the third and fifth being weak. In Ah 

 the fifth and seventh harmonicals are characteristic. The German U 

 is pretty well given with the fundamental note alone. These exam- 

 ples will make clear my meaning. 



Having gone through with this labor, by methods which I cannot 

 now even indicate, Helmholtz actually reconstructed the vowel sounds 

 out of pure notes by using a series of tuning-forks, which were made 

 to vibrate for any length of time by electro-magnetism. 



When, then, a human being utters merely a vowel sound, its pro- 

 duction requires that the cavity and opening of the mouth should 

 have exactly such a size and shape as strengthens the appropriate notes 

 to the proper degree ; so that it is indeed no wonder that an infant 

 requires the practice of a year or two before becoming practically 

 familiar with these delicate operations, the real wonder being that 

 children even learn to talk at all, for the construction of the conso- 

 nants is far more complex; and although we know, for the most 

 part, the manipulation necessary for their formation, their composi- 

 tion so far bafiies all attempts at exact analysis.* 



These illustrations will serve to give some slight idea of the mode 

 in which we speak ; and I now pass on to the consideration of the 

 wonderful and mysterious apparatus with which we receive and actu- 

 ally analyze the sounds that are presented to us. We have on the 

 screen a plan of the ear, not a correct drawing, for that would be so 

 complicated as to be of little use ; the sound-waves enter the outer 

 ear, and strike on this not tightly stretched membrane, which we call 

 the drum of the ear, and cause it to vibrate, to bend inward and out- 

 ward, keeping exact time with the sound vibrations themselves. To 

 this membrane, as you see, are attached three little bones, called, 

 respectively, the hammer, the anvil, and the stirrup. The membrane 

 shakes the hammer, the hammer beats the anvil, the anvil vibrates 

 the stirrup, and the stirrup sets in vibration the water in this strangely 

 shaped cavity, which is colored blue for distinctness. In this cavity, 

 which is not without its unsolved mysteries, the nerves of hearing 

 terminate, and transmit from it the sensation of sound to the brain. 



* The morning after the delivery of this lecture, I received the new work of Dr. Oskar Wolf, 

 "Sprache und Ohr," which contains an elaborate attempt at the analysis of the consonants, the 

 merit of which can, of course, be determined only by future investigations. 



