GAS 121 GAS 
< Intervals above Liston’s No Specific | Intervals above or| Liston’s Intervals above or], Liston’s 
Gases, and Mix-| or below the |" anq pire. || Gravities| below the Sound Notes and || Vejoci- | below the Sound | Notes and 
tures of such, | Sound with At) ponces in of the | with Atmospheric) Differences } ties of |with Atmospheric] Differences 
mented on.| mospheric Air, Gases. Air. in Sound. Air, in 
Bit fectets 5 b> f m = i = f m = 
Ether vapour {661.82 13 57) eX 42.82) 2,250. |—358.00 7 31) F 
Carburetted 4 
hydrogen . |644.59 13 CK—3.41 | 0.5554 | 259.63 5 32) F+45.63 
dydrogen - + (623.89 12 ce’ 40.89 || 0.0807 | 1111.10 22 96)a4K+41.10] 6899 |1093.57 21 95\b’hp—1.43 
h 177.97 1 7ICKX—5.18) 1.161 | —65.95 1 6 B2.05 
Ether vapour | - 
and com. air | 24.80 1 2/C%—11.21 
aoe pes i] C’42.38 |.0.97 C—0.97 | 114 
; tm ae if 18.88) \/0 +2. 0.977 10.03. 0 1| C'—0.97) 1149 | 14.77. 0 1) C'4.3.77 
Common Arr 0 0 Cc 1.000 00 0 C 1130 0 0 0 ct 
Carbonic and 
hydrog. gases} 32.06 1 Cp + 3.95 
Oxygen and 
_nhitreg. gases | $2.69 1 C')+3.31 
Oxy; ++} 43.191 B’ +-2.81 |) 1.108 45.26 1 4| B’0.74) 1064] 5315 1 4 B43.86 
Olefant gas . | 61.87 1 Ch—4.87 || 0.9745 | +1044 0 1 C’—0.56 
Chlorine and 
olefiant gases||37.91 3 12) Bpp+2.09 
Chlorine. . . |160.73 3 14 A+0.27|/2.713 440.55 9 38|E’b—0.55 
(Carbonic acid |189.04° 4 16] A’p3.04 1.500 178.93 4 15|4’>+7.08 || 922 | 179.55 4 164’) +-6.45 
Nitrous oxide [197.59 4 17} Ap—0.59 || 1.603 208.33 4 18|Ap—0.33 
_ A very interesting memoir on the sounds produced 
by hydrogen gas, was published in the Journal de Phy- 
sigue, vol. lv. p. 165, by Dr Delarive of Geneva. ir 
Higgins and Brugnatelli were the first who published 
an account of the sounds produced by hydrogen gas 
passing through a small tube. Professor Pictet made 
a series of experiments on these sounds, and describes 
the various musical phenomena which are produced, 
He explained the influence on the sounds occasioned by 
the length or width of the tubes, and the situation 
where the hydrogen is burned ; but it was left to Dr 
Delarive to assign a very ingenious and plausible cause 
_ for the phenomena: He supposes, that a brisk vibrato- 
ry motion is caused by the continual production and 
condensation of aqueous vapour ; and that, in order to 
roduce a sound, this vibratory motion must be able to 
rmonise with the dimensions of the tube, and is 
then regulated and equalised by the regular reflexions 
from the tube, so as to constitute together a clear musi- 
al sound. For this purpose there must be a great dif- 
_ ference of temperature in the air, and the tube near the 
flame. For farther information on this subject, see Ni- 
cholson’s Journal, vol. i. p. 129, and vol. iv. p. 23; and 
Dr Thomas Young’s Natural Philosophy, vol. ii. p. 267. 
_GASSENDI, Perer, an eminent French philoso- 
pher, was born at Chantersier in Provence, in 1592. 
After giving very premature indications of his talents, 
which he did before he had reached his fifth year, he was 
sent.to school at Digne, where he made rapid progress 
in the Latin language, and acquired a decided pre-emi- 
. nence among his school-fellows, He was next sent to 
study philosophy at Aix, and when he had continued 
there two years, he returned to his father’s house, with 
the view of prosecuting his studies in retirement. A 
vacancy, however, having taken place at Digne, he was 
invited, at the early of sixteen years, to teach rhe- 
_toric in that city ; and he had scarcely filled this situa- 
tion for three years, when he was appointed to the va- 
vant chair of philosophy in the university of Aix. ‘The 
authority of Aristotle was still acknowledged in almost 
VoL. X. PART J. 
‘\ 
(¢) 
all the public schools of France, and it required no or« 
dinary boldness to call in question his philosophical sys- 
tem. Gassendi, however, did not seruple to expose the 
errors of that great master, in the indirect form of para~ 
doxical problems, which he published under the title of 
Ezercitationes Paradoxice adversus Aristotelem. This 
work obtained for Gassendi the particular friendship of 
Nicholas Peires¢, president of the university of Aix, 
who succeeded, by the assistance of Joseph Walter, pri« 
or of Vallette, in procuring for him a canonry in the ca- 
thédral church of Digne, where he was admitted to the 
degree of doctor in divinity, and i ee rector of the 
church. This new situation, which enabled him to re« 
sign his chair at Aix, allowed Gassendi the uncontrolled 
management of his time. He composed a second book 
of his Evercitaiiones Paradoxice, for the pu of 
pointing out the absurdity of the Aristotelian logic, and 
intended to pursue the subject to a much greater ex. 
tent, but he was violently assailed by the powerful ad- 
herents of the ancient sage, and he considered it pru- 
dent to abstain from any farther attacks upon the Aris- 
totelian system. 
In the year 1628, Gassendi travelled into Holland, in 
order to make himself acquainted with the philosophers 
of that country ; and during his visit, he composed an 
apology for his friend the learned Mersennus, in an- 
swer to the attack of Robert Fludd on the subject 
of the Mosaic philosophy. Upon his return to Digne, 
he resumed with great diligence his astronomical stu~ 
dies. He had the good fortune of being the first 
that observed a transit of Mercury over the sun’s 
disc. This happened on the 7th of November 1631, 
the transit having been calculated by Kepler. In the 
year 1641, Gassendi was called by a lawsuit to Pa- 
ris, and gained the acquaintance and esteem of the dis- 
tinguished characters of that metropolis, and particu- 
larly of the Cardinal Richelieu, and his brother the Car- 
dinal of Lyons. He had long preserved an intimacy 
with the great Descartes; but a circumstance now oc- 
curred, which for a long time interrupted their friend- 
8 
