and other acouflic Difcoveries of Dr. Chiadni. 397 
5. It does not affe&t the nerves of the performer; fora 
perfon fcarcely feels a weak agitation in the fingers; whereas 
in the harmonica, particularly in concords of the, lower 
notes, the agitation extends to the arms and even: through 
the whole body of the performer. 
6. The expence of this infirument will be much Jefs ia 
future than that of the harmonica. 
7. When one of the tubes breaks, or any other part is 
deranged, itcan be foon repaired, and at very little expence ; 
whereas, when one o! the glaffes of the harmonica breaks, 
it requires much time and is very difficult to procure another 
capable of giving the fame tone as the former, and which 
will correfpond fuficiently with the feries of the reft. 
Though Dr. Chladni has been much occupied with the. 
conftruction and improvement of the euphon, he has, how- 
ever, ftill continued his refearches refpecting the theory of 
found, and colieéted materials for a continuation of his eflay 
before mentioned, which contain abundance of valuable 
matter. In one paper, which may be found in the Berlin. 
Mufical Journal for Augutt 1792, he has giyen fome -very 
accurate obfervations re{pecting the longitudinal vibrations 
of a firing, firft announced by himfelf, which depend upon. 
laws of nature totally different from thofe of the ufual yibra- 
tions. Dr. Chladni tranfmitted alfo, a few years ago, to the 
Friendly Society of the Searchers into Nature at Berlin, in 
order to fulfill his duty as a member, two eflays, one.of 
which contained obferyations on the tones produced in a 
tube by burning inflammable air; from which it, appears 
that thefe tones, firft remarked by Mr. De Luc, are nothing 
elfe than pipe tones, as the fonorous body is not. the tube 
but the column of air contained in it... The other eflay. was 
entitled Collections towards promoting a better Explanation 
of the Doétrine of Sound. ‘The author here {hews, how this 
part of the fcience of nature, not yet fufficiently elucidated 
hy any one writer, ought to be treated, according, to his 
opinion, 
