THE PYROPHONE. 445 



cal sound or tone, is that which produces a continuous senfcation, and 

 of which one can appreciate the musical value. Noise is a sound of 

 too short a dui-ation to be appreciated well, as the noise of a cannon, 

 or else it is a mixture of confused and discordant sounds like the roll- 

 ing of thunder. For a single sound to become a musical sound, that 

 is to say, a tone corresponding to one of the intonations of the musical 

 scale, it is necessary that the impulse and, consequently, the undula- 

 tions of the air should be exactly similar in duration and intensity, 

 and that they should return after equal intervals of time. In its 

 change to the musical state, however dull and confused the noise may 

 be, it becomes clear and brilliant. Like the diamond, after having 

 been polished and cut according to the rules of art, it has the brill- 

 iancy for the ear which the former has for the eye. This is what 

 takes place in singing -flames. Very imperfect in its beginning, 

 hoarse, roaring, or detonating, it does not come nearer the musical 

 sound, properly so called in the chemical harmonica, as it is termed, 

 still, by means of reiterated trials, the sound of the single flame in the 

 tube, the lumen philosophicum, as it is elsewhere called, can it be 

 musically produced in every case. 



It has long been known that a flame traversing a glass tube under 

 a certain pressure produces a musical sound. The eminent savayit, 

 Prof. Tyndall, to whom the greater part of the deep questions in 

 physics are no mysteries, has studied singing-flames, but it must be 

 admitted that singing-flames have only penetrated into the dominion 

 of art in consequence of the discovery made by M. Frederick Kastner 

 of the principle which allows of their being tuned and made to pro- 

 duce at will all the notes of the musical scale, to stop the sound instan- 

 taneously and mechanically; as in keyed instruments, the sound is regu- 

 lated and subdued as desired. It is thus that the modest harmonica 

 chlmique, lumen philosophicutn of natural philosophers has, in the 

 pyrophone, attained to the character of a real musical instrument ; 

 tliis happy result supports the remark that the observation in Nature 

 of the phenomenon of sound may conduct man, if not exactly to the 

 invention of music, at least to endow the art with resources which in- 

 crease its power. The sound of the pyrophone may truly be said to 

 resemble the sound of a human voice, and the sound of the ^olian 

 harp ; at the same time sweet, powerful, full of taste, and brilliant ; 

 with much roundness, accuracy, and fullness ; like a human and im- 

 passioned whisper, as an echo of the inward vibrations of the soul, 

 something mysterious and indefinable ; besides, in general, possessing 

 a character of melancholy, which seems characteristic of all natural 

 harmonies. The father of this young philosopher, a member of LTn- 

 stitut de France, and a learned author, who died in 1867, treating on 

 cosmic harmonies, insists on this peculiarity : 



" The harmonies of Nature," said he, " which, in their terrible grandeur as 

 well as in their ineffable sadness, have ever charmed the philosopher, poet, and 



