An elementary book on electricity and magnetism and their applications . niac (the scientific name is ammonium chloride).The carbons are made with very large surfaces. 18. Chemical depolarization. If some substance is addedto the liquid of the cell which will combine with the hydrogenas quickly as it isformed, the polariza-tion will evidently beavoided. This is thefoundation of thesecond method of de-polarizing. Varioussubstances may beused for this purpose,such as manganesedioxide, potassiumbichromate, and so-dium bichromate bat-tery, which is oftenused for experimentalpurposes
An elementary book on electricity and magnetism and their applications . niac (the scientific name is ammonium chloride).The carbons are made with very large surfaces. 18. Chemical depolarization. If some substance is addedto the liquid of the cell which will combine with the hydrogenas quickly as it isformed, the polariza-tion will evidently beavoided. This is thefoundation of thesecond method of de-polarizing. Varioussubstances may beused for this purpose,such as manganesedioxide, potassiumbichromate, and so-dium bichromate bat-tery, which is oftenused for experimentalpurposes in isolatedplaces where no formof electric power isavailable, is a zinc-carbon battery with a liquid composed ofsulphuric acid in which potassium bichromate or sodium bi-chromate has been dissolved. When this cell is in operation,polarization is prevented by the immediate combination withthe potassium bichromate of the hydrogen which is liberatedfrom the sulphuric acid. Carbon is used for the positive platein this cell because the bichromate of potash will attack and. and Chromic Acid Fig. 7. — Plunge battery with four bichro-mate cells. 18 ELECTRICITY AND MAGNETISM Carbon destroy copper. In the bichromate battery the zincs are gen-erally arranged so that they may be lifted out of the fluid whenthe cells are not in use, because the fluid eats up zinc whenthe circuit of the cell is open. From this comes the nameplunge battery (Fig. 7). The ordinary proportions in which the solution for this type of bat-tery is made up are as follows, the parts being measured by weight:180 parts of water 25 parts of commercial sulphuric acid12 parts of bichromate of potash, or bichromate of crushed bichromate should first be dissolved in the water atboiling temperature, after which the acid may be added slowly to the cooled solution. Always add the acid toj the solution ; never add the solution to theacid, as serious burns are apt to result. zinc When manganese dioxide is used asa dep
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectmagnetism, bookyear19
