FOREIGN CORRESPONDENCE. 
259 
Tilcro is a ssliglit error in the figures on the riglit, repi'csenting 
oligoclasc and uugito. 
During our visit to England, in tlie autumn of last year, M. Prost 
published the following note (which has escaped our attention until 
now) upon certain vibrations of tlie earth observed at Nice during tlie 
winter of 1857-1858, and since that period: — "When I came back 
to Nice in October, 1857, my pendulum remained perfectly quiet for 
about twenty days ; but it began to move suddenly on the 4th Nov., 
and oscillated with considerable intensity. The movement was accom- 
panied, as usual, by that of the glass hangers of the chandeliers. 
These oscillations, after having diminished gradually for some days, 
showed a new activity about the 18th, which lasted till the 2 2d. 
I have been able to ascertain that the date of the 4th November 
corresponds to that of the violent earthquake which took place at 
Meneggio on the Lake of Como, and the other dates with shocks 
observed on the 19 th at Pontevedra and at Lisbon, and on the 21st 
at Lisbon and Porto. Since then the oscillations of my pendulum have 
been almost permanent, presenting very rare intervals of repose ; and 
their intensity augmented again on the 15th December, and lasted 
for a very long time ; the glass hangers oscillated without interruption 
np to the first days of January, 1858. It was during this period that 
the earthquake at St. Denis-du-Sig, in the province of Oran, took 
place, on the 1-tth December ; then the terrible shocks felt at Naples 
and in La Pouille on the night of the IGth and 17th December, which, 
after having been felt on the 17th at Hcrnosand, in Sweden, on the 
20th at Agram, in Croatia, continued for a long time, and occasioned 
many disasters in those countries. Again, on the 25th, shocks were 
felt at St. Veit, in Austria, and at Admont and Kosegy in the valley 
of Eros. Their sphere of activity spread itself, therefore, to a great 
distance, for during the same period, i. e. fi"om the 20th December, 
shocks of earthquake happened in succession at Brousse, up to about 
the 15th of January, and on that day were felt at Katibor, in Silesia, 
whilst on the 11th an earthquake took place at Martinique, and on 
the 2Cth there was one at Parma." 
About the end of February, 1858, the oscillations of M. Prost's 
pendulum began to diminish gradually ; in the months of May and 
June there were very few. But they began again in July, and con- 
tinued with increasing intensity until the night of the 4th and 5th 
August, when a shock took place about half-past two a.m., which 
awoke the inhabitants of Nice out of their sleep. " It is, therefore, 
certain," says M. Prost, in conclusion, " tiiat this phenomenon of 
oscillation, which had never yet been observed, is in connexion with 
earthquakes ; but that it differs from the latter inasmuch as, instead 
of being sudden and violent, like a shock, it manifests itself as a 
vibration, the duration of which may be hours, weeks, or even 
whole months." 
Our accomplished friend, M. Pisani, has lately received from Con- 
stantinople samples of a new mineral found in the interior of Turkey, 
and which presents a rather remarkable composition. It is seen to 
