72 Natural Formation of various Metallic Oxides and Salts. 
to the Academy two pairs of spectacles which he calls rostral 
spectacles.—Drs. Laserre and Costa communicated some cri- 
tical remarks on M. Moreau de Jonnés’s note read as above.— 
M. Arago communicated extracts from two letters relative to 
the late appearance of two comets.—M. Mathieu, in the name 
of a committee, read a favourable report on a memoir of per- 
spective geometry, or a new method of describing bodies geo- 
metrically, by M. Cousinéry—M. Lonchamp read a memoir 
on the effects of a high temperature applied to the evapora- 
tion of liquids.—M. Julia-Fontanelle read a memoir on the 
native hydrate of sulphur discovered in the department of 
the Aude.—M. Arago, in the name of a committee, gave a 
favourable report on the voyage of discovery made from 1822 
to 1825 under the command of Lieut. Duperrey. 
Aug. 29.—M. Berard, of Briangon, communicated a new 
memoir on the theorem of Fermat.—Dr. Lassis addressed a 
letter to the Academy on the contagion of Typhus.—M. Ma- 
gendie presented a memoir on Hydrophobia, by Dr. Maro- 
chetti—_M™M. Cuvier and Duméril made a favourable report 
on M. Barry’s memoir rélative to the action of the atmo- 
sphere on respiration.—M. Civiale read a memoir on Jithon- 
éripty, or the new method of breaking the stone in the bladder. 
XII. Intelligence and Miscellaneous Articles. 
NATURAL FORMATION OF VARIOUS METALLIC OXIDES AND 
SALTS. 
PoE following is an abstract of a paper on this interesting 
subject, read before the Royal Society on the 17th of No- 
vember last : several other cases of the same nature will be found 
in our last volume, pp. 153 and 395. 
On the Changes that have taken place in some ancient 
Alloys of Copper; in a letter from John Davy, M.D. F.R.S., 
to Sir Humphry Davy, Bart. Pres. R.S.—In this letter Dr. 
Davy, who is pursuing a train of scientific researches in the 
Mediterranean, describes the effects which time and the ele- 
ments have produced on various Grecian antiquities. The 
first he examined was a helmet of the antique form found in a 
shallow part of the sea between the citadel of Corfu and the 
village of Castrades, which was partly covered with shells and 
with an incrustation of carbonate of lime. Its entire surface, 
as well where invested with these bodies as where they were 
absent, presented a mottled appearance of green, white, and 
red. The green portion consisted of the submuriate and the 
: carbonate 
