88 
MR. GROVE ON THE ELECTRO-CHEMICAL POLARITY OF GASES. 
some other electricians who experimented with him in the year 1838, viz. that when 
two wires forming the terminals of a powerful battery were placed across each other, 
and the voltaic arc taken between them, the extremity of the wire proceeding from 
the positive end of the battery was rendered incandescent, while the negative wire 
remained comparatively cool ; it was at that time believed that there was some effect 
exhibited here extra the voltaic 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 be- 
came more incandescent than that of the negative, from the greater heating effect 
developed at the point when the disruptive discharge took place. I suggested as 
an explanation of this phenomenon, the possibility 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 oxygen a greater heating 
effect was developed. This, with some other impressions, 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 satis- 
factory, there were many arguments in its favour, and the fact strongly impressed 
my mind as evincing 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 1848, while experimenting with Mr. Gassiot with a nitric acid battery 
consisting of 300 well insulated cells, I made the following experiment : — Two wires 
of platinum ^th of an inch in diameter, forming the terminals of the battery, 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immersed in distilled water; the negative wire was then gradually withdrawn until it 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 w^as apparently sus- 
pended in air and hanging from the wire ; it appeared sustained by a repulsive action 
like a cork ball on a 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 depressed, and 
divided into little concave cups, which were in a continual agitation. When the con- 
ditions were reversed and the negative wire immersed, the positive wire being at the 
surface, similar phenomena ensued, but not nearly in so marked a manner ; the cone 
was smaller, and its base much more narrow in proportion to its height. 
This experiment, the beautiful effect of which requires to be seen to be appreciated, 
indicates a new mode of transmission of electricity partaking of the electrolytic and 
disruptive discharges. Not possessing a battery of this enormous intensity, I have not 
been able to examine this phenomenon more in detail ; but I have from time to time 
* Philosophical Magazine, 1840, p. 478. 
