NATURAL PHILOSOPHY. 151 



playful questions and remarks that have been made to me — 

 1 ' Whether for the future, before beginning a concert, the hearers are 

 to be examined, and a place allotted to each accordingly, where he 

 may be able to hear with satisfaction ?" — "Whether instrumentalists 

 are to be separated into two divisions, one of which is to use the 

 A right pitch, the other the A left ?" &c. I content myself with 

 simply asserting the fact as I have found it. 



The reason for this difference of hearing is probably that the 

 external passage of the ear is set in vibration, like a speaking- 

 trumpet, by the sounds that enter it, and that this vibration modifies 

 the pitch of the entering sound more or less according to the form of 

 the individual ear. 



The supposition that the waves of sound, before impinging on 

 the tympanum, have to pass through a thin film which covers it, 

 is less probable, since such a film would of course be subject to 

 change from time to time, and thus the whole phenomenon might 

 be altered. 



As may be supposed, I have not as yet been able to collect any 

 information on this subject. 



If, in measuring the number of vibrations of musical notes, the 

 above circumstance has not been taken into account, some modest 

 doubt of the accuracy of the results may not be altogether unreason- 

 able. — Philosophical Magazine, No. 136. 



Professor Helmholtz, by a series of experiments, has been led to the 

 hypothesis that each narrow fibre of the auditory nerve is destined for 

 the perception of notes of a particular pitch, and is excited when the 

 note which strikes the ear corresponds in pitch to that of the elastic 

 formation in connexion with the fibre. According to this, the per- 

 ception of different tones would realize itself through the simtdtaneous 

 excitation of the fibre which corresponds to the primary note, and of 

 certain others, corresponding to the incidental notes. — Poggendorff's 

 Annalen. 



NEW SOUND-FIGURES FORMED BY DROPS OF A LIQUID. 



If a drinking-glass, or a funnel of about three inches diameter at 

 the edge, be filled with water, or alcohol, or ether, and a strong note 

 be made by drawing a violin-bow on the edge, a Sound-figure will be 

 formed on the surface of the liquid, consisting of nothing but drops 

 of liquid. If the vessel gives the fundamental note, the figure forms 

 a four-rayed star, the ends of which extend to the four nodal points ; 

 but if the note which the vessel gives be the second higher, the star 

 wdl be six-rayed ; and if the vessel gives still higher tones, other more 

 numerously rayed stars are produced. — F. Melde; Poggendorff's 

 Annalen. 



VELOCITY OF THE SOUND OF THUNDER. 



The Eev. Mr. Earnshaw, in a paper on "A New Theoretical 

 Determination of the Velocity of Sound," concludes that it would 

 appear there is no other limit to the velocity with which a 

 violent sound is transmitted through the atmosphere, than that 



