ARRHENIUS, iir-ra'ni-us. SvaxrE (1859 —). A Swedish physical chemist. He was horn near Upsala, and studied physical science at the university of that city. After a brief period of teaching at his alma meter lie spent several years abroad. carrying on original investigations in collaboration with some of the best European chemists and physicists of the day, and in 1891 was made professor in the University of Stock holm. Arrhenius's researches have resulted in one of the most important among the recent eon tributions to science. Confining his attention almost entirely to the relations between electro lytic phenomena and the chemical and physical properties of substances, he succeeded in estab lishing on a firm basis a general theory, which is now' all but universally accepted by the scientific world, viz., the so-called theory of electrolytic dissociation. According to this theory, a sub stance whose aqueous solution is capable of con ducting electricity is broken up in solution into parts charged. some with positive, others with negative electricity Thus, ordinary brine con tains, aecordmg, to Arrhenius's theory, electro positive 'ions' of the metal sodium, and, sepa rated from them. electronegative ions of chlo rine. The theory reminds one of the old dual istic view of the nature of chemical composition, advanced by Davy and Berzelius in the first part of the Nineteenth Century: and, in the opinion of many authorities, may lead to a revival of those views in some modified form. What is cer
tain is that the theory of electrolytic dissocia tion furnishes an excellent explanation of a host of chemical phenomena which would otherwise remain entirely unintelligible, and that it cor relates a number of different facts, between which no connection could otherwise be detected. Arrhenius's publications include Sur la conducti Lilita des electrolytes (1884), a (hi German) on electro-chemistry (1902), and a number of original monographs contributed to the Zcitschrift fiir physikulische Chemie. See DISSOCIATION.
(Gk. 'Apindaier, Arrhidaios). An illegitimate son of Philip of Macedon by Philinna. a dancing girl of Larissa. He was at when Alexander died. in B.C. 323, and, though almost an imbecile, was elected king, under the name of Philip, with the understanding that if a son were horn to Rosana, the widow of Alexander, he should be associated with Arrhithe us in the Government. The next year Arrhidams married Adea, called Eurydice, the granddaugh ter of Perdieeas 11. Two years later he and his wife were captured by Polysperelmn, the leader of the cause of Alexander's son, born of Boxana, and both were put to death by the order of Olym pias, the grandmother of the young king.