410 Scientific Intelligence. — Hydrography . 
ward these openings. The difference of level between the two 
extremes may amount to several feet. It is obvious that, were 
a line drawn, by hypothesis, when the Baltic was at its greatest 
elevation, and were its level measured at the same point when it 
is lowest, it would seem lowered much beyond what it would 
have been found, had the two corresponding observations been 
made when the level was at its mean height. It is therefore 
this mean height which it is of importance to determine, in 
either case, — a task which, without doubt, presents great diffi- 
culties, but which is absolutely necessary to insure the correct- 
ness of the observations. — Such is the substance of M. Hsell- 
strom’s opinion on the subject, as stated in his memoir. It is to 
be regretted, that the precautions of which he speaks, had not 
been taken into consideration by M. Bruncrona, as they would 
have rendered the observations more useful, which he made in 
1820, at thirty different points, by means of the pilots under his 
command, as well as the care he has taken to have lines engrav- 
ed upon various rocks to mark the level of the sea, and answer 
as so many points of reference to future observers. — M. Hosll- 
strom passes rapidly, and with a sort of contempt over an idea 
received among the inhabitants of the small islands on the coast 
of Bothnia, and which, to be the opinion of these ignorant and 
perhaps incorrect observers, has not been entirely rejected by 
some philosophers ; namely, that the level of the surface of the 
sea does not fall, but that the bottom is gradually raised, at 
least in the north of Sweden. The author throws ridicule upon 
this opinion, by saying, that, since this effect is not observed 
upon the shores of the Islands of Gothland and Oeland, which 
are calcareous or sandy, but only upon those of the Gulf of 
Bothnia, which are composed of gneiss abounding in felspar, we 
must attribute to this latter rock an aptitude for rising which the 
others do not possess. It belongs to the Neptunists to see whe- 
ther this objection appear to them sufficient to make them 
change their opinion . — Bulletin Universe! 
CHEMISTRY. 
7. On Metallic Titanium. —Dr Walckner of Freyberg, in 
the Breisgaw, has lately described cubical crystals of metallic 
titanium which he observed in iron-slags from the Upperland of 
