Book Description

From the PREFACE. This little treatise is designed to present in English a summary of the recent work on the electrical conductivity of liquids, and to aid, if possible, in the more complete adoption of the Kohlrausch system of units in this country. It was in 1897 that Kohlrausch and his associates first proposed the new unit of conductivity based on the ohm. Kohlrausch and Holborn recalculated all the old important conductivity results in terms of this new unit and published them in their "Leitverm�gen der Elektrolyte." Thereafter, consequently, no advantage was to be derived from the continued use of the old and less rational system of units. The new system was soon in general use throughout Germany, but its adoption in other countries has been much slower, and up to the present time there are some writers, especially in this country and in France, who continue to use the old system based on the Siemens unit. Most of the conductivity results of the last eight years will be found in the appendix, recalculated, when necessary, to reciprocal ohms. The confusion in this field has, unfortunately, not been confined to the units alone, but is found also in the use of the symbols employed to indicate specific conductivity, equivalent conductivity, and many of the other related magnitudes. For instance, A. is employed by some to indicate specific conductivity, by others to indicate equivalent conductivity, and is sometimes expressed in Siemens units and sometimes in reciprocal ohms. The transport number of the anion has long been indicated by n, but occasionally a writer employs p for this purpose. The word "normal" is used by many physical chemists in the sense of molecular normal, but the avoidance of ambiguity demands that it be used in physical chemistry, as in analytical chemistry, to indicate equivalent normal only. The nomenclature and symbols employed in this book are essentially the same as those used by Kohlrausch and Holborn. In a few instances, however, I have ventured to introduce a change for the sake of simplicity.... I have attempted to avoid paralleling Kohlrausch and Holborn's "Leitverm�gen der Elektrolyte," except in the case of certain standard methods, which must appear in any book of this character. Considerable space has, therefore, been given to transport numbers and to the theory of electrolytic dissociation. On account of the increasing interest in non-aqueous solutions and in non-aqueous solvents, a relatively large amount of space has been devoted to these subjects. The greater portion of this text was written in 1903, and it should therefore have appeared some time ago, except for my own absence from this country during part of the time since, and for delay due in nowise to negligence on the part of the present publishers. The references and the conductivity tables have been brought down to 1905, wherever possible. For any failure to do this, I hope the preceding apology will suffice....