337 
On the Recognition of Noises. 
Academy,” and in the “ Naturforscher,” a treatise on noises, 
ne shows that if noises are heard with the same nerves as 
sounds of deep or of high pitch there must exist a subjective 
relation , between noises and sounds of great wave lengths, 
and again respectively between noises and sounds of short 
wave lengths. 1 his is supported in faCt by daily experience. 
Music lepresents the discharge of cannon by the sounds of 
the drum, and the meaning is understood. The intensity of 
the detonation does not here come into play, since no one 
can confound a distant cannon shot with a pistol shot close 
at hand. On the contrary, a cannon shot, a rifle shot, the 
snapping of a percussion cap, and that of a small eleCtric 
spaik, foim a series from a deep to a high pitch, so that 
noises also can be divided into low and high, according to 
t le legions of the cochlea, which are principally excited in 
each case. 
T. he tone of the tissues whose nerve-fibres are most 
stiongiy excited by a noise, and which determines the pitch 
of tie explosive noise, must appear the more distinctly in its 
peculiai ity the more distant the source of the noise. For 
whilst a cannon shot near at hand certainly excites all the 
fibres of the auditory nerves, a similar shot in the distance 
scarcely affeCts those nerves which are more feebly affected, 
so that a part only of the auditory nerves comes into play! 
Indeed, in the lattei case the relation with a deep sound is 
much gieatei than in the former. With high explosive 
noises this difference is not so striking, because they are 
not loud enough to admit of a sufficient variation in the 
distance. 
The better to understand what happens we must first 
reply to the question as to the simplicity of explosive 
noises, that is whether they consist of one wave or of a series 
of .waves. Brucke, therefore, instituted experiments with 
different noises by means of a Koenig’s apparatus for demon- 
strating the flame-images of the vowels — somewhat modified 
and he obseived that a good clap with the hands produced 
as a rule only one projection in the flame. The explosion 
of soap-bubbles filled with detonating-gas gave also generally 
only one projection. If a small organ-pipe (1050 vibrations) 
was sounded simultaneously to measure the length of the 
sound-waves the ignition of percussion caps gave one pro- 
jection only, while without the organ-pipe several such 
were obtained. In the former case the feeble secondary 
impulses were overpowered by the stronger impulse of the 
pipe. 
Brucke next examined explosive noises resembling the 
