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action alloy ammonia ammonium ampere per square anode antimony applied arrangement atoms attached bath battery becomes boiling brass Britannia metal brush carbonate cathode cell cent chemical chloride circuit clean coating cobalt coil colour composition compound connected containing copper sulphate crystals decimetre deposit dilute dissolved dynamo electricity electro-deposition electro-metallurgy electro-motive force electrolytic electrotyping excess film gold gutta-percha heat hydrochloric acid hydrogen impurities insoluble iron latter lead liquid magnetic melted mercury metal method mixture mould nickel nitrate nitric acid object obtained ounces oxide passing placed platinum plumbago pole polished portion potash potassium cyanide precipitate produced proportion pure quantity readily recommended by various removed resistance salt silver silver chloride simple immersion sodium sodium carbonate soluble solution specific gravity square decimetre square inch substance sufficient sulphide sulphuric acid surface temperature thickness thin tion washed weight wire zinc zinc sulphate
Page v - Embracing the Application of Electrolysis to the Plating, Depositing, Smelting, and Refining of various Metals, and to the Reproduction of Printing Surfaces and Art-Work, &c. BY WALTER G.
Page 61 - An ampere is the unit of measurement of the strength of the current. Ohm's law: The strength of a current varies directly as the EMF and inversely as the resistance In arranging cells, the strongest current is obtained when the internal resistance of the battery is equal to the external resistance of the circuit. In divided circuits the amount of current that will flow through different branches is inversely as their resistances. Electrolysis is the decomposition (by the electric current) of compounds...
Page 326 - Saturated solution of ferric chloride in hydrochloric acid to which a little nitric acid has been added.
Page 251 - Thus treated, the plate will not be greatly liable to rust ; but if it is to be stored for any length of time, it must be treated like an ordinary engraved steel plate and covered with a protective film of wax.
Page 353 - Water 57.2° 60.8° 64.4° t18° 75.a° 82.4° 86' 8 45.7 43.7 41.9 40.2 37.1 34.2 32 0 12 36.3 34.9 33.5 32.2 29.9 27.9 27.0 16 31.2 30.0 28.9 27.9 26.1 24.6 24.0 20 28.5 27.5 26.5 25.6 24.1 22.7 22.2 24 26.9 25.9 24.8 23.9 22.2 20.7 20.0 28 24.7 23.4 22.1 21.0 18.8 16.9 16.0 the liquid. The diminution of resistance accompanying a rise of temperature should be especially marked. 85. Theory of Electrolytie Reaction.
Page 353 - IX No. of Parts of Copper Sulphate Temperatures (Fahrenheit) By the term specific resistance in the above tables is meant the absolute resistance in ohms of a column of the liquid 1 square centimeter in cross-section and 1 centimeter long; in other words, it is the resistance of a cubic centimeter of Specific Gravity of Acid Temperatures (Fahrenheit) W 39.2° 46.4° 53.6° 60.8° 68° 75 2...
Page 50 - A star-shaped group of copper sheets, surrounded by crystals of copper sulphate, is placed in the bottom of a glass jar. Water, to which a few drops of sulphuric acid have been added, is poured in until the cell is nearly full, and then a zinc plate or " crowfoot" is hung from the upper edge of the jar.
Page 185 - The leaf is placed between two plates, one of polished steel, the other of soft lead, and is then passed between rollers which exert a considerable pressure. The leaf thus imparts an exact impression of itself, and of all its veins and markings, to the...
Page 284 - The principle underlying the various processes in use for this purpose consists in passing a current of electricity, of suitable strength, from an anode of the impure metal through a solution of copper salt and depositing the pure metal upon a convenient cathode ; at the same time allowing for the removal of such insoluble impurities as gradually form a slimy sediment upon the bottom of the vat and guarding against the excessive accumulation of soluble impurities in the liquid itself. The...
Page 134 - ... of sulphuric acid, may be employed with advantage, but considerable latitude is permissible in the proportions adopted. The deposition of the copper upon the surface of the iron is almost instantaneous, and, indeed, a long exposure in the solution produces a slimy precipitate.