ing the months of heavy snowfall, lead me to believe that my
_confreres_ (geologists) were disinclined to follow up a correct and
actual prospectus of these valuable serpentinous localities.

Before locating, or going into details of these classes of rock as a
mineral repository, I intend to treat on the subject as regards their
mode of existence and origin.

Serpentine is diffused under the head of "metamorphic rocks," while, in
the widest sense, according to Studor and others, mineral metamorphism
means every change of aggregation, structure, or chemical condition,
which rocks have undergone subsequently to their deposition and
stratification, or the effects which have been produced by forces other
than gravity and cohesion.

There fall under this definition the discolouration of the surface of,
for instance, black limestone, by the loss of its carbon, the formation
of brownish red crusts in rocks of limestone, sandstone, many
slatestones, shales, granite, &c., by the decomposition of compounds of
iron, finely disseminated in the mass of the rock, the change in rocks
consequent in the absorption of water, and the crumbling of many
granites and porphyries into gravel, occasioned by the decomposition of
the mica and felspar.

In its more limited sense the term "metamorphic" is confined to those
changes of rock which are produced directly or indirectly by agencies
seated in the interior of the earth. In many cases the mode of change
may be explained by our physical or chemical theories, and may be viewed
as the effects of temperature or of electro-chemical actions adjoining
rocks or connecting communications with the interior of the earth, also
distinctly point out the seat from which this change proceeds. In many
other cases the metamorphic process itself remains a mystery, and from
the nature of the products alone do we conclude that such a metamorphic
action has taken place.

Serpentine is generally believed to have been originally deposited as a
sediment, and to have acquired its present compact crystalline character
through the subsequent action of various chemical, or mechanical,
agencies. It is known to be a _hydrated silicate of magnesia_ with about
equal parts of silica and magnesia, and contains 12 per cent. of water
with varying proportions of iron, chromium manganese, alumina and lime,
has a specific gravity of 2.7, and weighs about 169 lbs. to the cubic
foot. It is found both in a soft and very compact