392 Scientific Intelligence—Mechanical Philosophy. 
copper, each of which was attached to a copper wire. ‘Two nuts of 
the same metal, sliding upon a vertical glass rod, and to which the 
two wires were attached, permitted their being brought near togeth- 
er, or removed at pleasure. Having suspended a prepared frog by 
the body to the upper wire, the legs were placed upon the lower one. 
The apparatus being thus arranged, whenever (the discs being re- 
spectively covered with the red and violet rays) a contact was formed 
between the extreme parts of the two wires, evident signs of con- 
tractions were observed in the frog.—Note by Prof. Gazzeri. 
Having experimented two summers since, upon the solar spec- 
trum, in exactly the same way, except that a very delicate galvan- 
ometer was used instead of a frog, no electricity could be obtained 
By et ate Beh oe M. F.—Idem. 
5. Leech Bites—Dr. Lowendhart mentions a method of check 
ing the profuse bleeding from leech bites, which is simple and effect- 
ual. The edges of the little wounds are drawn together with a fine 
needle and thread. The thread being drawn through the cuticle - 
gives no pain, and the bleeding is at once suppressed. (Jour. 
Chir. Med. Jour. VI. 86.)—Idem. 
6. Professor Hanstein.— Terrestrial Magnetism.—Letters: have 
been received from Professor Hanstein and his companions, to the 
19th of February. On,the 12th of September they left Tobolsk, 
aiid travelled on sledges, the cold being at —40° R., so that the fro- 
zen quicksilver could be cut with a knife. On the 31st they arrived 
at Tornsk; on the 21st of January, 1829, at Krasnojarsk, and on the 
7th. of February, at Irkutsk, which is about 4000 versts from ‘To- 
bolsk. ‘They afterwards visited Kiachta, and crossed the frontier of 
China ; but the most agreeable result is, that the desired object of 
the j journey is accomplished, as the observations have proved per- 
, and the magnetic pole is found. . Centuries will 
petbaips elapse before Siberia will be again so thoroughly observed. 
When the letters were dispatched, it was resolved that the journey 
should be extended to Nertschink ; from which gece: Professor Han- 
stein would return to Krasnojarsk. . His companion, I nt Due, 
was to go alone to Jakutzk, 2700 versts N. E. of Irkutzk, or eet 
haps proceed down the river Lena to the Frozen Ocean, and they 
in d ve meet oe at Jeniseisk in September or October. (New 
