twenty-five per cent., by the
agency of lime, carbonic acid, or sulphuric acid. Lime is cheap and
harmless. Other circumstances recommend his series of experiments. A
scientific reporter writes mysteriously of the discovery of a very
simple and easy method of extracting sugar from the beet-root; with an
apparatus which costs very little, any one may make his sugar with as
much facility as he boils his pot.

* * * * *

Of the EXPEDITION TO CENTRAL AFRICA, we learn from the _Athenaeum_ that
letters from Dr. Barth and Dr. Overweg have been received in London by
Chevalier Bunsen, by which it appears that up to October last the
travellers were still detained in the kingdom of Air. A previous
communication gave an account of difficulties and dangers which they had
met with on entering that country; the inhabitants of which had shown
themselves hostile to them, so that their fate seemed entirely to depend
on the protection of the Prince En-Nur, sultan of the Kelves. This
hoped-for protection they have been fortunate enough to secure; though
it appears not to have been sufficient to insure their safety beyond
Tin-Tellus, the residence of the Prince, in consequence of which they
have been obliged to forego the exploration of the country, and to
remain with the Prince. They have however been enabled, while thus
stationary, to collect a good deal of oral information,--especially
respecting the tract of country to the west and southwest of Ghat:
which, instead of being a monotonous desert, proves to be intersected by
many fertile wadys with plenty of water. Among these novel features, not
the least interesting is a lake, between Ghat and Tuat, infested with
crocodiles. At the date of Dr. Barth's letter (2d of October) the
travellers were on the point of setting out on an excursion to Aghades,
the capital of Air; the new sultan having promised them his protection,
and the valiant son-in-law of En-Nur accompanying them on their
journey. The latitude of Tin-Tellus has been found to be 18 deg. 34' N.;
the longitude has not been finally determined. The rainy season lasts
till September, and thunder-storms occur daily in the afternoon between
two and three o'clock, accompanied by a west wind, while at other times
it blows from the east. It seems yet uncertain when the expedition will
be able to start for lake Tchad.

* * * * *

GEN. RADOWITZ, the late Minister of Prussian