. The Family tutor . alsoupon the decomposition in each cell,equally with that between the platinumelectrodes. The same phenomena whichvve notice in the decomposing cell takesplace also in each battery cell. Water isdecomposed, and the hydrogen is given offfrom the positive plate, while the oxygencombines with the zinc, and thus escapesdetection. Therefore, no fluid not anelectrolyte is suitable to excite a , water acts, for this purpose, only bythe decomposition of the water, and oxida-tion of the zinc. The presence of theacid is useful only so far as it com-bines with the oxide o
. The Family tutor . alsoupon the decomposition in each cell,equally with that between the platinumelectrodes. The same phenomena whichvve notice in the decomposing cell takesplace also in each battery cell. Water isdecomposed, and the hydrogen is given offfrom the positive plate, while the oxygencombines with the zinc, and thus escapesdetection. Therefore, no fluid not anelectrolyte is suitable to excite a , water acts, for this purpose, only bythe decomposition of the water, and oxida-tion of the zinc. The presence of theacid is useful only so far as it com-bines with the oxide of zinc constantlyaccumulating on the zinc plate, whichmust be removed as fast as formed, inorder to keep up a steady flow of electricity. From what has been said, we can seethat a decomposing cell interposed in thecircuit will give us an exact account of theamount of electricity flowing. Such aninstrument has been called by Faraday, avoltameter (measurer of voltaic electri-city), and is sliown in Fig. 46. It diiFers. Fig. 46. from the decomposing cell, in being asingle cell, and having a ground glasstube at top bent twice, so as to deliver theaccumulating gases into a graduatedair-vessel, in which their volume is mea-sured. A more simple form of the appa-ratus is easily constructed, as shown inFig, 47, which is a short piece of glasstube, with two corks and a bent tube (a.)The electrodes p, p, pass through thecorks, and should terminate in broad plates of platinum foil. A common formof the instrument is seen in Fig. 48, whichhas only one tube, and that is graduated.
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Keywords: ., bookcentury1800, bookdecade1850, bookpublisherlondo, bookyear1851
