Electro-Chemical Analysis (Paperback)

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: accordance with data of the resistances of the baths determined for the work done under an earlier system. The wires, both those in the battery rooms and those in the laboratory proper, are covered with rubber, and those in the laboratory are further encased in oak moulding, but this rather for the sake of appearance than for protection. The whole installation, as well as the other fittings of the room, has a very neat and finished appearance. (Science, 13, 697 (1901).) Before taking up the description of the details to be observed in the electrolytic precipitation of individual metals, it may not be uninteresting to briefly trace the history of the introduction of the electric current into chemical analysis. 6. HISTORICAL. Although the early years of last century show considerable activity in electrical studies, the efforts were mainly directed to the solution of the physical side of electrolysis. To Gaultier de Claubry probably belongs the credit of having first (1850) applied the current to the detection of metals when in solution. His efforts were wholly directed to the isolation of metals from poisons by depositing the same upon plates of platinum. When the precipitation was considered finished the plates were removed, carefully washed, and the deposited metals brought into solution with nitric acid, and there tested for and identified by the usual course of analysis. The current was evidently very feeble, as the time recorded as necessary for the deposition varied from ten to twelve hours. Gaultier considered this method reliable in all instances, but especially recommends it for the separation of copper from bread. In testing for zinc he employed a strip of tin as anode, but states that a platinum plate will answer as well. In Graham-Otto's Lehrbuch der Chemi...