150 
THE GEOLOGIST. 
not forget a singular circumstance, namely, that the town of Mont- 
pellier is built upon a mine of j)ure mercury ^ He had found this 
precious metal in many of the streets, in the rue Carbonerie, the rue 
de I'Universite, the Grande rue, the Halle aux Poissons (fish-market), 
&c. In 1837, M. Marcel de Serres and Leymerie described the 
ground in which the metal lay, and moreover made known the existence 
of the latter in the soil of a field which had always been remarkable 
for its sterility. A few days ago, M. do Eouville and M. Marcel de 
Serres have again written upon the same subject. 
The reason why so many observers should have called attention to 
this fact is doubtless to be found in the curiosity of such a discovery. 
In fact, pure quicksilver has, up to the present time, not only been 
considered a rare mineral, but has almost always been found near the 
middle strata of the earth's crust, and in those strata which repose upon 
crystalline rocks. It has, indeed, been mentioned by Mr. Daniel Sharpe 
as having been met with in the Tertiary sand on which the capital of 
Portugal is built; and in 1847, some workmen who were laying down 
gas-pipes at Lyons were surprised at seeing a remarkable quantity of 
quicksilver filtering, as it were, through the soil in the very centre of 
the town. The metallic mine indicated by Mr. Sharpe was actually 
worked for some time ; but the presence of mercury at Lyons was 
attributed to the facility with which this slippery metal, much employed 
in the manufactories, escapes from the hands of the workmen. 
At all events, M. de Rouville has recently discovered, at Montpellier, 
a new deposit of metallic mercury, which, until now, had never been 
remarked. In building the foundation of a new fish-market, near the 
place where the old one stands, a quantity of earth was removed, and 
a species of pudding-stone, containing the precious metal, laid bare. 
M. de Rouville describes this pudding-stone as formed of large frag- 
ments of limestone strongly cemented together, containing a little 
silica. It is of a reddish colour, and reposes on grey fresh-water marl, 
in which M. Paul Gervais formerly discovered the teeth of a new 
species of monkey. According to M. Marcel de Serres, the following 
is the description of the soil in which the mercury is found : — 
"Uppermost, a bed of reddish mud, then a thin layer of grey marl 
mixed with gravel and calcareous pebbles about as large as the hand. 
Next comes a layer of whitish marl, and under this a very greyish 
calcareous sandstone, containing calcareous pudding-stone and pebbles 
