444 M. Oersted on [Juke, 



conductor must be capable of transmitting a part of the current 

 A equal to the current B ; and if we suppose A to possess a 

 stronger intensity than B, the transmission of the former will be 

 still greater. 



Exper. 7. — We tried the effect of the complex circuit upon 

 the needle of the multiplier, and we found it considerably aug- 

 mented, by increasing the number of the elements of the circuit, 

 even in cases in which the number did not increase the effect 

 upon the compass. We obtained this result by experiments 

 with 6, 13, and 22 elements. It appears then that the intensity 

 of the power increases in the circuit with the number of the 

 elements, which is perfectly conformable to what happens in 

 Volta's pile. The circuit had no sensible effect upon the com- 

 pass when the communication was made by the multiplying 

 wire. 



Exper. 8. — A platina wire, about 0*004 of an inch in diame- 

 ter, was not ignited by a thermoelectric circuit composed of 13 

 elements, but which was nevertheless capable of causing the 

 compass to deviate 28 degrees ; yet a hydroelectric circuit pro- 

 ducing an equal effect upon the compass, was quite sufficient to 

 ignite the same wire. This difference is derived from the too 

 weak transmission of the thermoelectric current by the platina 

 wire. During the communication effected by this wire, the 

 needle of the compass indicated only 2 or 3 degrees of deviation. 

 An iron wire, about 0-008 of an inch in diameter, was not 

 ignited. The communication effected by this wire produced a 

 greater deviation than the platina wire, but only by 5 degrees. 

 We must wait for the current produced by a thermoelectric 

 apparatus composed of several hundred elements, before we 

 shall be able to ignite a metallic wire. 



Exper. 9. — We were unable to produce any sensible che- 

 mical action by the thermoelectric circuit ; those fluids which 

 have the greatest conducting power resisted its action ; 

 for instance, nitric acid, solution of soda, and many metallic 

 solutions. We shall mention only one of these experiments, 

 which, frequently repeated, appeared to produce some chemical 

 effect. We placed a piece of blotting paper moistened with 

 solution of sulphate of copper between two perfectly new five 

 franc pieces ; the precaution was taken to put the two pieces in 

 contact with the paper on the sides which had similar impres- 

 sions, and the thermoelectric current was passed through the 

 two pieces of metal and the moistened paper. In a quarter of 

 an hour some parts of the silver were slightly covered with 

 copper. But as this trace of metallic precipitation did not resist 

 washing accompanied with slight friction, we are disposed to con- 

 sider this experiment as too questionable. During the time that 

 the two pieces of silver with the paper formed part of the cir- 

 cuit, not the slightest effect was produced upon the compass, so 

 that this small piece of moistened paper may be said to have 



