Foreign Literature and Science. 389 



the diameter was meKed in five seconds. A careful estimate 

 of the calorific power of this instrument, was made by Prof. 

 Pictet, in successive intervals of one minute each, by immer- 

 sing the conducting wire in a- silver cup which weighed 

 fifty-nine grains, containing seventy-two grains of water, into 

 which a thermometer u'as plunged with a very small bulb. 

 The bulb rested on the conducting wire in the bottom of 

 the cup. When the conducting wire was about eight inches 

 long, the thermometer rose in one minute from 43° to 82^° 

 Fahrenheit, and in one instance, with a very short wire, 

 from 43° to 111° Fahrenheit, in the same time. With a 

 short platina wire as a conductor, the water soon acquired 

 the boihng temperature ; and what was well worthy of re- 

 mark, the ebullition ceased instantly on the interruption of 

 the circuit, and irt*^an^(;/ re commenced on its renewal, 

 without any appreciable time between the cause and effect. 

 This fact appears to prove that the progress of heat in the 

 galvanic battery, from its connection with electricity, is, like 

 the latter, altogether inappreciable, notwithstanding that it 

 moves this solid matter. 



W^hen the conjunction between the poles was formed by 

 two platina wires, of different diameters, placed parallel to 

 each other, the larger wire was always ignited, but the 

 smaller one never. When the same two wires, attached 

 end to end, formed the connection, the smaller wire was 

 always ignited, when attached to either of the poles. 



A sewing needle, placed at right angles to the conjunctive 

 wire and above it, acquired magnetism in three seconds. 



When the conjunctive wire was placed exactly in the di- 

 rection of the magnetic meridian, a magnetised needle, free- 

 ly suspended under it, declined 72° from the N. to the W. 



Two conjunctive wires were placed very near each oth- 

 er, but without touching ; they then cut each other at right 

 angles, in a horizontal place. A magnetic needle was then 

 brought under them, and its north pole stood between the 

 south and east, and when placed above them, the same pole 

 stood between the north and west. The conjunctive wire 

 was twisted into a spiral form and placed with its axis in the 

 magnetic meridian. The needle being placed under the 

 spiral, its north pole deviated 70° from N. to W. and when 



