. Carnegie Institution of Washington publication. WORK OF BINGHAM. EXPERIMENTAL. APPARATUS. CONDUCTIVITY. The Kohlrausch method of measuring conductivity, with Wheatstone bridge, telephone receiver, and induction coil, was employed. It was not difficult to read to less than of 1 per cent. The bridge-wire was made of "manganin" and was calibrated before beginning the work. The resistance coils were carefully standardized. In order to work successfully with acetone, it was necessary to provide cells of special construc- tion, so as to avoid the presence of rubber or wax, which woul
. Carnegie Institution of Washington publication. WORK OF BINGHAM. EXPERIMENTAL. APPARATUS. CONDUCTIVITY. The Kohlrausch method of measuring conductivity, with Wheatstone bridge, telephone receiver, and induction coil, was employed. It was not difficult to read to less than of 1 per cent. The bridge-wire was made of "manganin" and was calibrated before beginning the work. The resistance coils were carefully standardized. In order to work successfully with acetone, it was necessary to provide cells of special construc- tion, so as to avoid the presence of rubber or wax, which would be dissolved by the solutions. The cells were made of hard glass with ground-glass stoppers, and had the form shown in fig. 20. The glass tubes carrying the electrodes were sealed into both the upper and the lower walls of the glass stopper. The distance between the electrodes thus remained permanently fixed. The zero-bath was prepared by filling a large battery-jar with clean, finely crushed ice, moistened with water. This was placed in a pail made of compressed paper pulp, and the annular space filled with finely crushed ice. Thus protected, the bath could be used for a much longer time than with the methods usually employed. The 25° bath was of the usual form, the stirrer being driven by means of a hot-air engine. An Ostwald regulator was employed. The thermometers were regulated to tenths of a degree. They were tested at the beginning of the work. Burettes and flasks were care- fully calibrated. VISCOSITY. The viscometer was of the form recommended by A fixed volume of the liquid to be measured was introduced into the apparatus. The. FIG. 20. Physiko-Chemische Messungen, 2d ed., p. 260. 81. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Carnegie Institution of Washington. Washington, Carneg
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