m, and
selenium are found in old silver coins and also in ores which were
formerly supposed to be nearly pure sulphides and oxides of lead and
silver. From 400,000 pounds of silver and 5,000 pounds of gold were
obtained twelve pounds of platinum, two pounds of palladium, and several
pounds of selenium. To obtain these the gold is first precipitated from
the solution by ferrous chloride, all the other metals by iron turnings.
The precipitate is first submitted to the action of ferric chloride to
dissolve the copper, and the residue is fused with charcoal and soda to
separate the selenium. The regulus from this operation is dissolved, and
a compound of selenium and palladium, or of these with platinum, is
obtained. They are composed of equal atoms of the two metals and form
hard brilliant plates. The presence of these metals in coins is less
remarkable than in such ores as those of Commern and Mechernich on the
west bank of the Rhine. These ores occur as small granules of galena in
a soft sandstone, their origin being still a mooted point. The ore
yields a very soft and pure lead, though the presence of pyrite prevents
the manufacture of the virgin lead used in making the best brands of
white paint.

A FRENCH MOUNTAIN WEATHER STATION.

The French government has placed on the top of the Puy de Dome a
meteorological observatory, which, as that is the highest land in
France, answers to our stations on Mt. Washington and Pike's Peak. It
is, however, constructed in a style very different from those somewhat
forbidding abodes. At the top is an observatory tower, placed on a
platform, and upon this is placed the anemometer, especially constructed
to withstand the force of the storms. Within the tower is a well hole
fifty feet deep, which leads to a tunnel more than a hundred feet long,
at the end of which is placed the keeper's house. This is a massive
building, situated a short distance from the top, where it is partly
protected by rocks. The whole work cost $45,000, and $20,000 more will
be spent in supplying it with apparatus.

MIGRATION OF THE LEMMING.

A new theory has been broached to explain the migrations of the Norway
lemming, a variety of field mouse. Every few years an immense body of
these animals leaves their habitat and proceed westward, attacking every
obstacle in front in preference to flanking it, until it reaches the
sea, which the little animals boldly enter, only to perish there. No
conceivable advan