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violence of the shocks felt in that part of America are considered, he 
is of opinion, that the agreement of the earthquakes, in April, 1812, 
with the simultaneous eruption of the volcano of St. Vincent, was 
fortuitous. 
In 1772, the little group, situated some leagues to the north of 
the chain of the Caucasus, and composed of the trachytic moun- 
tains called Pechstein, and the calcareous hill Metschuka, was 
shaken by an earthquake. The warm springs, known by the name 
of the baths of the Caucasus, issue from the foot of the limestone 
hill, and deposit, as well as all the cold brooks, considerable quanti- 
ties of calcareous tuff. It might be supposed, observes M. Necker, 
that the thermal springs indicate the existence of some portion of 
the original heat of the trachyte ; and that the earthquake of 1772, 
by which a portion of the hill, Metschuka, was engulphed, was only 
the effect of volcanic activity. This, he says, is possible; but it ap- 
pears to him much more probable, that the cold and warm springs 
had formed large cavities in the limestone hill, the falling in of the 
roof of which produced the shock and attending phenomena. 
The earthquakes in Jamaica in 1692, M. Necker is of opinion 
were non-volcanic, because there were only subsidences of the 
ground, and because only water, sand, and gravel were ejected. 
The earthquake in the plain of Bogota, 16th November, 1827, he 
is tempted to consider non-volcanic, the country being gypsiferous 
and saliferous; but he admits that it may have been of a mixed 
nature, in consequence of the great adjacent volcano of Popa- 
yan being, at the same time, in activity. The earthquakes on the 
coast of Chili, he is of opinion, may have a similar origin. 
M. Necker gives a list of earthquakes extracted from Mr. Lyell’s 
“« Principles of Geology,” and arranges them under the heads—vol- 
canic, non-voleanic, and of doubtful origin. 
In the first list he includes the earthquakes felt at Ischia, 
February 2nd, 1828; Java, 1699, 1772, and 1786; Sumbana, April, 
1815; Quito, Feb. 4, 1797; Sicily, March, 1693, 1790; Guati- 
mala, 1773; Kamtschatka, 1737; Peru, Oct. 28, 1746; Iceland, 
1725; Teneriffe, May 5, 1706; Sorea, (Moluccas) 1693; Lisbon, 
Noy. 1, 1755. 
Non-Volcanic.—Murcia, 1829; Lahore, Sept. 1827 ; Lissa, in the 
Adriatic, 1833; Foligno, Jan. 15, 1832; Cutch, June 16, 1819; 
Cumana, Dec. 14, 1797; the Caraccas, March 26, 1790; Calabria, . 
1783 to 1786; Bechstan, 1772 ; and Jamaica, 1692. 
Doubtful Origin. —Bogota, Nov. 16, 1827; Chili; Quebec, Dec. 
1791; Nipon, Japan, August 1, 1783; and Martinique, 1772. 
Thus, though M. Necker reduces considerably the power of vol- 
canic agents, yet he is far from denying that a weak volcanic move- 
ment may be propagated over considerable surfaces; and he men- 
tions, in conclusion, the following instances, as not generally known, 
of probable connexions between earthquakes and volcanic eruptions. 
The great eruption of Vesuvius, which commenced the 21st of Fe- 
bruary, 1822, was preceded by an earthquake at Geneva, and in the 
province of Bugey, in France, on the 19th of February ; and, before 
