ed with
respect to the decomposition of _water_, and under so many circumstances
which might be supposed, if anything could, to exert an influence over it,
that I may be excused entering into further detail respecting that
substance, or even summing up the results here (732.). I refer, therefore,
to the whole of the subdivision of this series of Researches which contains
the account of the _volta-electrometer_ (704. &c.).

786. In the next place, I also consider the law as established with respect
to _muriatic acid_ by the experiments and reasoning already advanced, when
speaking of that substance, in the subdivision respecting primary and
secondary results (758. &c.).

787. I consider the law as established also with regard to _hydriodic acid_
by the experiments and considerations already advanced in the preceding
division of this series of Researches (767. 768.).

788. Without speaking with the same confidence, yet from the experiments
described, and many others not described, relating to hydro-fluoric,
hydro-cyanic, ferro-cyanic, and sulpho-cyanic acids (770. 771. 772.), and
from the close analogy which holds between these bodies and the hydracids
of chlorine, iodine, bromine, &c., I consider these also as coming under
subjection to the law, and assisting to prove its truth.

789. In the preceding cases, except the first, the water is believed to be
inactive; but to avoid any ambiguity arising from its presence, I sought
for substances from which it should be absent altogether; and, taking
advantage of the law of conduction already developed (380. &c.), I soon
found abundance, amongst which _protochloride of tin_ was first subjected
to decomposition in the following manner. A piece of platina wire had one
extremity coiled up into a small knob, and, having been carefully weighed,
was sealed hermetically into a piece of bottle-glass tube, so that the knob
should be at the bottom of the tube within (fig. 68.). The tube was
suspended by a piece of platina wire, so that the heat of a spirit-lamp
could be applied to it. Recently fused protochloride of tin was introduced
in sufficient quantity to occupy, when melted, about one-half of the tube;
the wire of the tube was connected with a volta-electrometer (711.), which
was itself connected with the negative end of a voltaic battery; and a
platina wire connected with the positive end of the same battery was dipped
into the fused chloride in the tube; being however so bent,