Recherches sur la Conductibilité Galvanique des Électrolytes. I: La conductibilté des solutions aqueuses extrêmement diluées déterminée au moyen du dépolarisateur. II: Théorie chimique des électrolytes.

Stockholm: P.A. Norstedt, 1884.

First edition, the rare offprint issue, of Arrhenius’s doctoral dissertation containing his landmark discovery of the theory of electrolytic dissociation, one of the foundations of modern physical chemistry. Arrhenius was awarded the 1903 Nobel Prize in chemistry “in recognition of the extraordinary services he has rendered to the advancement of chemistry by his electrolytic theory of dissociation.” By 1880, it was known that solutions of certain compounds conduct electricity and that chemical reactions could occur when a current was passed. It was thought that the current decomposed the substance. In 1881, Arrhenius went to Stockholm to work with Erik Edlund at the Institute of Physics of the Swedish Academy of Sciences, where he began his study of the conductivity of electrolytic solutions. His aim “was to find a method for determining the molecular weight of dissolved non-volatile compounds by measuring electric conductivity. Soon he recognized that the state of the electrolyte was the matter of primary importance. Arrhenius completed his experimental work in the spring of 1883 and submitted a long memoir (in French) to the Swedish Academy of Sciences on 6 June 1883, with the results of his experiments and the conclusions he deduced from them. The memoir was published in 1884 under the title ‘Recherches sur la conductibilité galvanique des électrolytes’” (DSB). In this thesis, Arrhenius proposed a theory that substances were partly converted into an active form when dissolved. The active part was responsible for conductivity. In the case of acids and bases, he correlated the strength with the degree of decomposition on solution. “Arrhenius sent his work to several leading physical chemists, including Jacobus van't Hoff, Friedrich Ostwald, and Rudolf Clausius, who were immediately impressed” (Biographical Encyclopedia of Scientists). Arrhenius’s thesis was published in Bihang Till K. Svenska Vet.-Akad. Handlingar, Bd. VIII, 13. When it appears on the market it is almost always in the form of the journal issue, which for this journal is easily confused with the offprint, since only one article is published in each issue.

“In the first part of his memoir [‘La conductibilité des solutions aqueuses extrément diluées’ and ‘Recherches sur la conductibilité galvanique des electrolytes’], Arrhenius gave an account of his experimental work: He measured the resistance of many salts, acids, and bases at various dilutions to 0.0005 normal (and sometimes to even lower concentrations), and gave his results so as to show in what ratio the resistance of an electrolyte solution is increased when the dilution is doubled. It is true that Heinrich Lenz and Kohlrausch had made similar measurements, but they did not use such great dilutions. Like Kohlrausch, Arrhenius found that for very dilute solutions the specific conductivity of a salt solution is in many cases nearly proportional to the concentration (thesis 1) when the conditions are identical. The conductivity of a dilute solution of two or more salts is always equal to the sum of the conductivities that solutions of each of the salts would have at the same concentration (thesis 2). Furthermore, the conductivity of a solution equals the sum of the conductivities of salt and solvent (thesis 3).

“If these three laws are not observed, it must be because of chemical action between the substances in the solution (theses 4 and 5). The electrical resistance of an electrolytic solution rises with increasing viscosity (thesis 7), complexity of the ions (thesis 8), and the molecular weight of the solvent (thesis 9). Thesis 9 is an example of a proposition that is not correct. In addition to the viscosity of the solvent, its dielectric constant, not the molecular weight, is significant. Arrhenius worked, however, with a limited number of solvents (water, several alcohols, ether) for which the dielectric constant decreases approximately as the molecular weight rises. Arrhenius summarized Part I of his memoir as follows:

‘In the first six sections of the present work we have described a new method of measuring the resistance of electrolytic solutions. In this method we made use of rapidly alternating currents, produced by a depolarizer constructed for the purpose by M. Edlund. We have tried to show the use of this method, and to make clear the practical advantages which it possesses.’

“The main importance of Arrhenius’ memoir, however, does not lie in the experimental measurements or in the thirteen detailed deductions of Part I, but in his development of general ideas. These contain the germ of the theory of electrolytic dissociation (which received its definitive statement only three years later).

“In Part II (‘Théorie chimique des électrolytes’), Arrhenius gave a theoretical treatment of his experimental work, which he based on the hypothesis of the British chemist Alexander William Williamson and the German physicist Rudolf Clausius. In his famous article ‘Theory of Aetherification,’ Williamson suggested that in a chemical system a molecule continually exchanges radicals or atoms with other molecules, so that there is a state of dynamic equilibrium between atoms and molecules. Thus, in hydrochloric acid ‘each atom of hydrogen does not remain quietly in juxtaposition with the atom of chlorine with which it first united, but, on the contrary, is constantly changing places with other atoms of hydrogen, or, what is the same thing, changing chlorine.’ Williamson, however, did not assume that the radicals or atoms were electrically charged. Clausius advanced the hypothesis that a small fraction of a dissolved salt is dissociated into ions even when no current is passing through the solution. He did not state or calculate how much of the salt is thus affected.

“Arrhenius stated that the dissolved molecules of an electrolyte are partly ‘active,’ partly ‘inactive’: ‘The aqueous solution of any hydrate [by hydrates Arrhenius always meant hydrogen compounds like acids and bases] is composed, in addition to the water, of two parts, one active, electrolytic, the other inactive, non-electrolytic. These three substances, viz. water, active hydrate, and inactive hydrate, are in chemical equilibrium, so that on dilution the active part increases and the inactive part diminishes’ (thesis 15).

“Arrhenius gave no precise account of the nature of the active and inactive parts, however; he only indicated what they might be. He extended his hypothesis to other dissolved electrolytes (salts) and defined the ‘coefficient of activity of an electrolyte’ (corresponding to our notion of degree of electrolytic ionization) as ‘the number expressing the ratio of the number of ions actually contained in the electrolyte to the number of ions it would contain if the electrolyte were completely transformed into simple electrolytic molecules.’

After thesis 16 we find a number of chemical applications. Arrhenius asserted that “the strength of an acid is the higher, the greater its activity coefficient. The same holds for bases.” The dissociation becomes complete at infinite dilution of the solution (thesis 31); and in solutions of salts of weak acids, strong acids displace the weak acids (thesis 34). From a chemical point of view, thesis 23 is important: ‘When the relative amounts of ions A, B, C, and D are given, the final result is independent of their original form of combination, whether AB and CD, or AD and BC.’ The principle of the calculation of the degree of hydrolyzation by means of the law of mass action is given in thesis 29: ‘Every salt, dissolved in water, is partly dissociated in acid and base. The amount of the decomposition products is greater the weaker the acid and the base and the greater the amount of water.’

“In the last thesis (56), Arrhenius clearly stated the constancy of the heat of neutralization of a strong acid with a strong base: “The heat of neutralisation, set free by the transformation of a perfectly active base, and perfectly active acid, into water and simple salt, is only the heat of activity of the water,” where “heat of activity” is the heat used in transforming a body from the inactive to the active state. Arrhenius ended his memoir with a long summary, which begins as follows:

‘In the present part of this work we have first shown the probability that electrolytes can assume two different forms, one active, the other inactive, such that the active part is always, under the same exterior circumstances (temperature and dilution), a certain fraction of the total quantity of the electrolyte. The active part conducts electricity, and is in reality the electrolyte, not so the inactive part.’

“Although Arrhenius discussed electrolytic dissociation in his memoir of 1884, he nowhere used the word ‘dissociation,’ nor is there any explicit identification of the “active part” of the electrolyte with free ions in the solution. It is not so surprising that the acceptance of his theory was slow at first, above all because it had to overcome preconceived ideas that oppositely charged ions could not exist separately in solution. The influence and enthusiasm of Ostwald and van’t Hoff were consequently needed to make it widely known and accepted …

“[Arrhenius] presented [his thesis] to the University of Uppsala and defended it in May 1884, but his dissertation was awarded only a fourth class (non sine laude approbatur, ‘approved not without praise’) and his defence a third (cum laude approbatur, ‘approved with praise’). According to the then prevailing custom, this was not sufficient to qualify him for a docentship, which was a bitter disappointment to Arrhenius.

“The chemist Sven Otto Pettersson, professor of chemistry at the Technical High School of Stockholm, reviewed Arrhenius’ dissertation in the journal Nordisk Revy and praised it very highly, however: ‘The faculty have awarded the mark non sine laude to this thesis. This is a very cautious but very unfortunate choice. It is possible to make serious mistakes from pure cautiousness. There are chapters in Arrhenius’ thesis which alone are worth more or less all the faculty can offer in the way of marks.’ Pettersson referred here to the discovery of the connection between conductivity and speed of reaction. Per Theodor Cleve, speaking to Ostwald during the latter’s visit to Uppsala, remarked, ‘But it is nonsense to accept with Arrhenius that in a solution of potassium-chloride chlorine and potassium are separated from each other,’ and in his speech honoring Arrhenius at the Nobel banquet in 1903 he said: ‘These new theories also suffered from the misfortune that nobody really knew where to place them. Chemists would not recognize them as chemistry; nor physicists as physics. They have in fact built a bridge between the two.’

“Arrhenius sent copies of his thesis to a number of prominent scientists: Rudolf Clausius in Bonn, Lothar Meyer in Tübingen, Wilhelm Ostwald in Riga, and Jacobus Henricus van’t Hoff in Amsterdam. Ostwald, a physical chemist and professor at the Polytechnikum in Riga, was deeply impressed by the paper. He visited Arrhenius in Uppsala in August 1884, and offered him a docentship in Riga. Thanks to this, Arrhenius was appointed lecturer in physical chemistry at the University of Uppsala in November of that year. The English physicist Oliver Lodge was also impressed by Arrhenius’ paper, and wrote an abstract and critical analysis of it for the Reports of the British Association for the Advancement of Science in 1886.

“Through the influence of Edlund, Arrhenius received a travel grant from the Swedish Academy of Sciences which made it possible for him to work in the laboratories of Ostwald in Riga (later in Leipzig), Kohlrausch in Würzburg, Ludwig Boltzmann in Graz, and van’t Hoff in Amsterdam. During these Wanderjahre (1886–1890), he further developed the theory of electrolytic dissociation. Arrhenius’ theory was, however, slowly accepted at first, but because of neglect rather than active opposition. It was the enthusiasm and influence of Ostwald and van’t Hoff that helped to make it widely known. In 1887 Arrhenius met Walther Nernst in Kohlrausch’s laboratory. There, too, he carried out an important investigation on the action of light on the electrolytic conductivity of the silver salts of the halogens. In 1891 Arrhenius received an invitation from the University of Giessen, but he preferred the post of lecturer at the Technical High School in Stockholm, where he was appointed professor of physics in 1895 and was rector from 1896 to 1905. After refusing an offer from the University of Berlin, he became director of the physical chemistry department of the newly founded Nobel Institute in Stockholm, a post which he held until his death” (DSB).

8vo (225 x 145 mm), pp. [2], [1-3], 4-63, [1, blank], with one lithographed plate; [1-3], 4-89, [1, blank], uncut and unopened. Original printed wrappers. A very fine and completely unmarked copy.

Item #3160

Price: $1,850.00

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