386 
ON MERCUEY IN ALLUVIAL DEPOSITS. 
Br Dr. J. J. W. Watson, E.G.S. 
Dii. PnirsoN, of Paris, has drawn attention, in the April number 
of the Geologist, to the observations which have been made of the pre- 
sence of mercury in the soil and substrata of the town of Montpellicr, 
and, in your June number, another correspondent notices the finding of 
the same metal under circumstances so decidedly adventitious, how- 
ever, as to possess, I think, rather archaeological than geological inte- 
rest. The occurrence of this precious metal in rocks and mineral 
deposits of such ages as we should hesitate to assign for its matrix, most 
probably arises from its fluid natare admitting of its easy transport to 
distances far remote from those formations in which it exists in situ ; 
and, as furnishing something like the history of its presence in such 
apparently abnormal situations, the following account of its discovery at 
Ajaccio, in the Island of Corsica, may, perhaps, be considered worthy 
of insertion : — 
In the year 1811, a M. Matthien, an Engineer Officer of the French 
Army, was entrusted by Napoleon with the mineral survey of the 
Island, but, being re-called to his military duties in 1814, was cut off 
before Leipzig, leaving in the possession of his widow the notes he had 
made of his survey. These notes do not appear ever to have been 
ofBcially communicated, but among them was a memorandum to the 
effect that a deposit of mercury existed at Ajaccio. In 1847, a sewer 
was in course of construction near the barracks of the gendarmerie, 
at the Place Mourou ; and, in trenching below the vegetable soil, a 
large quantity of metallic mercury was found disseminated through the 
earth in minute globules — it is calculated that about 270 cart-loads of 
this mercuriferous soil were removed. Owing, however, to the persons 
engaged in making the drain being ignorant of its value, but a very 
small quantity of the metal was preserved, and, beyond the ordinary 
curiosity which such an occurrence would excite, the circumstance does 
not seem to have met with any attention until 1850, when a fresh 
quantity was discovered in digging the foundation of some houses in 
the Place Mourou, at a distance of about 500 yards from the locality 
where it was first found. This time attention was roused, and the 
existence of an important deposit capable of being profitably exploited 
