hews that the
globe presents the form approximately of a great octahedron
(eight-sided figure); and further, that the three axial planes which
such a form necessitates, may be described by existing circles round
the earth: the first being Himalaya and Chimborazo; starting from Cape
Finisterre, passing to India, Borneo, the eastern range of Australia,
New Zealand, across to South America, Caracas, the Azores, and so
round to Finisterre. The second runs in the opposite direction;
includes the Andes, Rocky Mountains, crosses Behring's Strait to
Siberia, thence to the Altai, Hindostan, Madagascar, Cape Colony, and
ending again at the Andes of Brazil. The third, which cuts the two
former at right angles, proceeds from the Alps, traverses the
Mediterranean by Corsica and Sardinia to the mountains of Fezzan,
through Central Africa to the Cape, on to Kerguelen's Land, Blue
Mountains of Australia, Spitzbergen, Scandinavia, and completing
itself in the Alps, from whence it started. These circles shew the
limits of the faces of the huge crystal, and may be divided into
others, comprising forty-eight in the whole. The views thus set forth
exhibit much ingenuity; and when we consider that metals crystallise
in various forms, and native iron in the octahedral, there is much to
be said in their favour.

We shall probably not be long before hearing of another gold field,
for Dr Barth writes from the interior of Africa, that grains of the
precious metal have been found in two rivers which flow into Lake
Tchad, and that the mountains in the neighbourhood abound with it.
Should the first discovery be verified by further explorations, gold
will be more abundant than it now promises to be, and Africa perhaps
the richest source of supply. Apropos of this continent, a French
traveller is about to prove from the results of a journey from the
Cape towards the equator, that the Carthaginian discoveries had been
pushed much further towards the south than is commonly supposed.

Agassiz, who, as you know, has become a citizen of the United States,
has had the Cuvierian prize awarded to him for his great work on
fossil fishes--an honour approved by every lover of science. This
distinguished writer says, in his latest publications on fossil
zoology, that the number of fossil fishes distributed over the globe
is more than 25,000 species; of mammifera, over 3000; reptiles, over
4000; shells, more than 40,000; numbers which greatly exceed all
former