539 
Two Fluids, and of Two Metals not in Contact, 
instance from the comparison of the iron circuits with s^inc and 
tin circuits; but why both alkalies with the iron circuits^ and 
the ammonia with tin circuits have in general a weaker action 
than water, — why, even with the combinations zinc~platina, 
zinc-silver, the alkalies have the ascendency over the water, is 
according to that view not conceivable. 
It is the same in all those cases in which two oxy-combinations 
are opposed to one another : water and carbonate of soda, sul- 
phuric acid and borax, sulphate of zinc and borax, sulphate of 
magnesia and borax. 
Perhaps here, from the carbonate of soda and borax being 
easily decomposable salts, and their solutions in the cases ex- 
amined always succumbing to that of the second oxy-combina- 
tion, a position from the Experimental Researches might be 
brought forward (§ 549) according to which substances are said 
to produce a more powerful current the more difficultly decom- 
posable they are, and vice versa. Thus might also be explained 
the general weaker action of dilute acids in comparison to 
water, since acidulated water is more easily decomposable than 
pure. However, this position appears hardly in unison with 
the fundamental principle of the chemical theory, that the affi- 
nity of the oxygen, chlorine, &c., for the zinc, is that which ex- 
cites the current ; for it might rather be supposed that this affi- 
nity can the less enter into activity the more strongly the oxy- 
gen, chlorine, &c., are retained by the positive element from 
which they are to be separated. Moreover, it cannot be applied 
to the alkalies, which in most cases increase the electromotive 
force and yet at the same time render water more decomposable 
than it is of itself. A further example, among tnany others, is 
afforded by salt and sal-ammoniac, two chlorides, the solution 
of the latter of which developes a stronger electromotive force 
than that of the first. It can hardly be admitted that sal- 
ammoniac is of more difficult decomposition than salt ! 
The solution of chlorine likewise, if I correctly understand 
Faraday^s view, could not, according to it, act differently from 
pure water ; for the chlorine is merely dissolved in the water, 
not combined with a body to form an electrolyte. Nevertheless 
it acts with zinc-platina, for instance, much more strongly than 
water. It acts, moreover, instantaneously on immersion, so that 
the action can scarcely proceed from formed chloride of zinc, 
which is also evident from the fact, that solution of chlorine, 
which has been frequently employed, containing therefore a 
considerable quantity of chloride of zinc, does not act in the 
least more powerfully than when pure. 
If, on the other hand, the action is derived from the chlorine, 
then again, according to this view, it cannot be conceived why 
