358 EXPERIMENTAL INVESTIGATIONS. 



circuit. Shortly afterwards I showed that with all, or at all 

 events a great number of metals, the positive terminal was more 

 heated than the negative, and that the portion of the crossed 

 wire which was positive became more incandescent than that of 

 the negative, from the greater heating effect developed at the 

 positive point when the disruptive discharge took place. I 

 suggested as an explanation of this phenomenon the possi- 

 bility that in air, as in water, or other electrolyte, the oxygen 

 or electro- negative element was determined to the positive 

 terminal, and that from the union of the metal with that of 

 oxygen a greater heating effect was developed. This, with 

 some other impressions, which turned out to be erroneous, I 

 mentioned in a letter to my friend Dr. Schonbein, not intended 

 for publication, but which shortly afterwards found its way 

 into print* 



Though by no means thinking that this explanation was 

 in every respect satisfactory, there were many arguments in 

 its favour, and the fact strongly impressed my mind as evin- 

 cing a very striking difference in character between the effect 

 of the discharge at the positive and negative terminals, and as 

 presenting, as far as it went, a distant analogy to the effect of 

 electrolysis. 



In the year 1 848, while experimenting with Mr. Gassiot 

 with a nitric acid battery consisting of 500 well-insulated cells, 

 I made the following experiment : Two wires of platinum 

 -jo-th of an inch in diameter, forming the terminals of the bat- 

 tery, were immersed in distilled water ; the negative wire was 

 then gradually withdrawn until it reached a point a quarter of 

 an inch distant from the surface of the water. A cone of blue 

 flame was now perceptible, the water forming its base, and 

 the point of the wire its apex ; the wire rapidly fused, and 

 became so brilliant that the cone of flame could be no longer 

 perceived, and the globule of fused platinum was apparently 

 suspended in air and hanging from the wire ; it appeared sus- 

 tained by a repulsive action like a cork ballon -&jet d'eau, and 

 threw out scintillations in a direction away from the water. 

 The surface of the water at the base of the cone was de- 

 pressed, and divided into little concave cups, which were i,n a 

 * Phil. Mag., 1840, p. 478. 



