By l)rot~. Emrix ,l. I{o[;s'rox and lgt,I~li[: q'iJ()~s()x. Tile wu'ious suggestions whi& have hitherto becn made tbr ~he stof :age of ele~_~tri('al em~rgy, in such mamw, r as t() readily permit its after recovery in tile fbrm of eleetrleal em'ren~, have fhih'd when attempted *o be carried into practice, either on account of their inh(;ren~ impraetieal)ility, or by re'lson of t,hc serious in(~'(lnvenienees and losses due chic, fly t() tim fi~]lowing: 1st, ']Plle exf(!llt of (!onduel, illg Sill, flier of /:lie storage a])parattlS required to be acted on, rendcring it cumbrous.
2d. The loss of e.mrgy due to evolution of g;is during the, operation .of eh'trging.
3(l. La('k of constancy and duration in the currents evolved after ,charging.
4th. The ]imlted eapaelty tbr storage due to tim proportion of active ;material being but a fi'action of that present.
The well-known 1)lant5 Secondary I)attery is open to all of the above inconveniences, "rod though admirable in its conception as a piece of scientific apparatus, yet lacks markedly the requisites of an economteal reservolr t:br electrical action. In the see(rodin T ba~tcu, as is well known, the, duration of action is chiefly depelMent upon the amount of surihee of the lead pl'ltes employed; the action of the current used to charge it t)ei~'>' praetieallv limited to [he surfhees of the plates, and the. charge received may theref'ore be designated as due .chiefly to polarizatlon. Moreover, the charge re.eeived is necessarily ,limited on aeeomlt of the evolution of gas.
]it is manifest that a Smee cell, or ('ell with vcrtleal plates, in an acid solution, could not be used in the process, fi)r the only eft:eeL would t)e .the evolution of the gases hy(h'ogcn and oxygen from ~he deeomposltion of water.
In the system of electrical storage devised by us, tile duration of -action :rod consequent eatlaeity for storage is independent of extent of .surfhee and dependent on the mass of material to be acted upon.
In our method we employ a saturated solution of' zinc sulphate , ,enclosed in a suitable vessel, at the bottom of which is placed a plat.e