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Scientific Intelligence, 
atemperature under 50°, the crystallisation of the mass takes , 
place, and there is a rise of temperature equal to 24° of Fahren- 
heit. When the carbonate of soda is used, small crystals or 
stars are abundantly precipitated, and the temperature rises 14° 
From a series of experiments made in this way. Dr Thomson 
concludes, that the latent heat of the water of crystallisation is in 
both cases the cause of the increase of temperature. — Ann. of 
Phil. iii. p. 169. 
83. On the Existence of Mercury in Sea-Water. Proust 
has remarked, as M. Hilaire Rouelie did before him, that ma- 
rine salt contains mercury. M. Proust has found mercury in 
every kind of muriatic acid that he has tried, and also in rock- 
salt. He suggests to navigators a method of ascertaining the 
existence of mercury in sea-water, by attaching a plate of gold, 
of two or three inches surface, to some part of the ship, so as to 
be constantly plunged in the water. Half an ounce of gold la- 
minated, he conceives would be sufficient for the purpose of as- 
certaining if it is amalgamated after a long voyage. M. Proust 
offers to be at the expence of the experiment, and desires any 
person willing to make it to apply to M. Lucas, agent to the 
Institute. — Mem, de Museum^ vii. p. 479. 
III. NATURAL HISTORY. 
. MINERALOGY. 
84. Merians Account of Alpine Limestone.-^Prc^Q^^oY Me- 
rian of Basle, in a little work entitled Ubersicht der Beschaf- 
fenheit der Gebirgsbildungen in den Umgebungen von Basel, 
1821,” we are informed, arranges the Jura limestone, oolite, 
shell limestone, and alpine limestone, as members of the same 
series ; and in the Basle district, these limestones rest upon the 
second or new red sandstone formation. This arrangement 
agrees with that previously adopted in this country. Raumer, 
in a geological tract published some years ago, stated, as a very 
probable conjecture, the identity of the shell limestone, oolite, 
and alpine limestone.” 
35. Oxygen in Roch-crystal. — Sir H. Davy has ascertained 
by experiment, that the water contained in vesicular cavities in 
