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Scientific Intelligence. 
This action he considers as galvanic ; and it is known, that some 
copper suffers comparatively little corrosion to that which takes 
place where the copper contains a small quantity of zinc or any 
other metal. In order to remedy this great practical evil, Sir 
Humphry Davy has shewn, that if a very small surface of tin is 
brought into contact with a surface of copper 100 times its size, 
it will render the copper so negatively electrical, that the sea- 
water is no longer able to corrode it. The same effect was pro- 
duced when a small piece of tin was made to communicate with a 
large surface of copper by means of a wire. We are informed by 
a friend (who saw the result of the experiment), that with a piece 
of Mr Mushet’s patent copper, a piece of common copper, and a 
piece of the one rendered negatively electrical by zinc, and sub- 
jected to the action of salt-water, the common copper was highly 
corroded, and the patent copper less so, while the negatively 
electrical copper was not affected at all. This elegant invention 
of Sir Humphry Davy, will, we doubt not, be well appreciated by 
-the government and the public. 
III. NATURAL HISTORY. 
MINERALOGY. 
^1. Notke regarding a Fossil having the smell of Truffles . — 
A singular fossil, which, on percussion, exhales an odour resem- 
bling that of truffles, has long been known in Italy under the 
name of abestiform Madreporite, Tartufoli, and xyloid Tartuf- 
fite, and resembles in smell the lignite of Wieliezka. It has 
been discovered at Ecouche, Frenay-le-Buffard (Orne), Curcy 
and Croisilles, near Aunay (Calvados). The tartuffite presents 
round or polyhedral stems, converted into acicular carbonate of 
lime, and seems to be allied to the monocotyledones. Its smell 
is probably the result of a new combination of the volatile 
principles of vegetables, and is owing to the presence of a bitu- 
men, susceptible of* being fixed in water, and sometimes in the 
proportion of 4 per cent. In France, the position of this fossil, 
according to Desnoyers, is in the calcareous, sandy, or argilla- 
ceous beds among the middle Jura oolites ; but in the Vicentin 
it occurs in the midst of the tertiary volcanic tufa. 
22. Forms of Crystallisation of Melted Sidphur. — Professor 
.Mitscherlich succeeded in obtaining crystals of sulphur of consi- 
