Acoustic Instrument.—Antiquities.— Moving Mountain. 465 
been derived from the percussion of the breast, according to the 
method of Auenbrugger, and a consideration of the facility with 
which sound is transmitted through solid bodies, suggested to 
the inventor the idea of studying, by the aid of similar interme- 
diums, the different sounds which the movements of the respira- 
tory and circulating organs produce in the interior of the chest, 
and of ascertaining whether the sounds which they emit might not 
give some more certain signs than those already known, as to the 
maladies with which they may be affected. The instrument 
which M. Laennec made use of for this purpose was a cylinder 
of wood, one foot in length, sixteen lines in diameter, and per- 
forated in the centre (like a pipe) by a bore of three lines in dia- 
meter. This instrument, when applied to the chest of a healthy 
individual when speaking or singing, only produces a sort of 
humming sound, more marked at certain points of the chest than 
others. But when there exists an ulcer on the lungs, the hum- 
mings sound changes into a phenomenon altogether singular, 
which the inventor calls pectoriloguy, and which the reporter 
M. Perey regards as sufficient for furnishing a certain and easy 
sign of any alterations in the state of the lungs. M. Laennec 
distinguishes three sorts of pecturiloquy, which, according to his 
anatomical researches, correspond with the size of the ulcers, 
with their state of vacuity or fullness, and with the consistency 
of. the matter which they inclose. 
ANTIQUITIES IN ARABIA PETRA. 
Mr.Banks, who has not yet returned to this country, has made 
drawings of the excavations at Uadi Moosa, walls which are sup- 
posed to have formed part of the public buildings of the ancient 
city of Petra. He has also visited and made‘drawings of Jerrasch, 
a city which by the ruins appears to have excelled in beauty and 
magnificence Palmyra and Balbec. 
LUNAR ATMOSPHERE. 
By an eclipse of a small star by the moon on the 5th of De- 
cember 1818, observed by Mr. J. B. Emmett, and published in 
The Annals of Philosophy, No. 77, it appears that the star was 
visible when really behind the moon’s disc; an effect that could 
be produced only by the refraction of the atmosphere of the 
moon. The existence of a lunar atmosphere has been very ge- 
nerally doubted, but certainly contrary to every philosophical 
principle. ———_ 
MOVING MOUNTAIN. 
In the vicinity of Namur there is a mountain of considerable 
elevation, from the foot of which there formerly issued a spring 
of water, remarkable for its copiousness and for never being ex~- 
Vol. 53. No. 254. June 1819. Gg hausied. 
