METALLIC WIRES BY ELECTRICITY. 473 
Number Quantity of Rise in temperature 
of jars. electricity. of thermometer. 
4* 5 0) 
51 0 
6 10) 
61 27°5 
7 35°0 32 
3* 4 0 
45 10) 
5 19°0 22°4 
54 32°3 27°5 
As the increase of temperature in the thermometer depends 
upon the mode in which the electricity is propagated through the 
water, the indications above show two modes of propagation. If 
the quantity of electricity 6 had been propagated through the 
water in the first experiment in the same manner as the quan- 
tity 61, then a rise in the thermometer of 23 lines must have 
occurred ; in the second example, the quantity 41, if propagated 
in the same manner as the quantity 5, must have produced a 
rise of 15°5 lines in the thermometer. Instead of these two 
quantities no appreciable change was observed. The discon- 
tinuous discharge was also evinced by a hollow sound, attended 
by a spark, in the water, which latter was scattered about. If 
the experiment is made with a greater distance between the 
platina points, and a consequently greater quantity of electricity, 
the vessel containing the water is often shattered in pieces. 
Position of the Points of Intermittence in Wires. 
The slightly varying elevations of temperature obtained in 
forty-nine experiments, with the same discharges, should not 
surprise us ; for we may easily suppose that in breaking through 
a fluid mass the discontinuous discharge is not always obliged 
to take the same course. This applies with like force to solid 
bodies, and especially to the metals when they are broken through 
and split into pieces. Wherever, on the contrary, the discharge 
is insufficient to dissolve the cohesion of the metal, it takes 
place more regularly, and seizes simultaneously the normal sec- 
tions of the wire, as the uniformity of the thermometrical changes 
on the incandescence of the wire and the dependence of these 
upon the diameters of the wire clearly show. We may now 
inquire concerning the position of the points of intermittence. A 
VOL. IV. PART XV. . 2L 
