the case at the petrifying dripping well near
Knaresborough. Every mass of it seems to
have been grouped round a centre, in more
or less concentric layers; and according to
the varying richness of the solution at different
times, so do the concentric-layers exhibit
a lighter and darker tint of green. A beautiful
theory is this; for it explains not only
the globular or rounded form of the masses,
but also the rich play of green tints observable
in all specimens of malachite.

It is a necessary consequence, or rather
a necessary preliminary, that ores of copper
should exist near the localities whence
malachite is obtained; for it is a solution of the
carbonate of metal which produces the gem
(if malachite may be called a gem, which it
almost deserves to be). It is not disseminated
in large masses, like a metallic ore; it seems
rather to have trickled into clefts and cavities,
which determine its dimensions. Rarely
can a piece be obtained weighing so much as
twenty pounds. It is softer than marble,
very much heavier, brilliant in its lustre, and
almost silky in the delicate gleam of its green
streaks; yet these qualities are marred by
the extreme difficulty of working it. Fragile
and yet obstinate, it sorely tries the patience
of the workman. A Russian, however, is
accustomed to patience; and he has
conquered in his time more obstinate things than
malachite.

Another curious circumstance connected
with malachite is, the extremely limited
number of spots where it has been found.
Siberia and Australia are nearly the only
two which can be named. In Australia the
discovery has been very recent; but in
Siberia malachite has long been known.
Until within a few years, the largest mass
obtained weighed about a hundred poods, (a
pood equals thirty-six English pounds); it
was obtained from the copper-mine of M.
Tourchaninoff, at Goumecheff (oh! these
Russian names), and is deposited in one of the
National Museums. But this has been beaten
into insignificance by a recent discovery, to
which are due the magnificent specimens of
malachite brought to England. The Messrs.
Demidoff, of St. Petersburgh, are the owners
of some copper mines in the Ural mountains;
and while the miners were in search of the
metallic ore, they on one fortunate day
lighted upon a mass of malachite, weighing
not less than three thousand poods. The
miners were able to detach this in one block,
and they then met with another thousand
poods weight, filling up clefts and crevices in
the surrounding rock. What a treasure this;
considering that a fair specimen of malachite
will bring fifteen shillings per English pound!
There is supposed to be a still larger deposit
of malachite near the spot whence this mass
was obtained: precious nuggets (albeit green)
which may by and bye put money into the
pockets of the proprietors.

But like other treasures, malachite requires
the hand of man before it becomes practically
valuable. The large masses crumble in the
air, generally into pieces of two to four pounds
weight; and the question arises how to work
so very brittle a material. It is not altogether
a new art; for museums and royal palaces,
in many parts of Europe, contain specimens
of inlaying or veneering with malachite.
But when Messrs. Demidoff made their grand
discovery, an incentive was given towards
the adoption of larger mechanical appliances.
They determined to establish a manufactory
of their own at St. Petersburgh, which they
placed under the care of M. Leopold Joffriand,
who left no means untried to obtain a mastery
over the material, and make it applicable to
ornamental purposes. How he succeeded in
his task, the malachite doors at the Crystal
Palace testified; and what difficulties he has
had to surmount, the following details will
show.

In the first place, then, it must be borne in
mind that the malachite is used, not in mass,
but as a thin veneer. The pieces are cut by
saws into veneers varying from a quarter to a
twelfth of an inch in thickness. To effect this
the block is cemented upon a carriage which
has a traversing motion along a little railway;
and the malachite is kept forcibly
pressed against the edge of a vertical circular
saw; fine sand and water are continually
applied to the cut, until the slice of malachite
is at length severed from the block. Thus is
the block sliced away, not quite so quickly
but much more carefully than the housewife's
quartern loaf. Where a curved surface is
to be covered with malachite, the saws for
cutting the veneer are bent to a corresponding
curvature; and an extremely delicate
and precarious process of cutting then
ensues.

The slices being cut, their junction into a
uniform plane is the next point attended to.
Here the most unwearied attention is called
for. In every piece of malachite, the dark
and light streaks of green form graceful
curves, varying infinitely in appearance. Now,
it would not satisfy an artistic eye to see
pieces joined together edge to edge without
any reference to varying tints of the surface;
there would be a mottled, confused, indefinite
jumble of bits of curves and bits of tints. The
workman, consequently, selects his pieces with
especial reference to their streakings, and
combines them edge to edge in such a way as
to carry out somewhat like a principle of
design—not stiff and formal, but just sufficient
to satisfy the eye by a kind of intelligibility
of arrangement. This is very difficult
to accomplish, on account both of the smallness
of the pieces and the variation of their
shape. Every little fragment has its edges
cut by means of a copper wheel. For each
joint there must be two or three little copper
grinding wheels employed, one to give the
convexities or protuberances to one edge, and
the other to impart the concavities or depressions