covery, however, was made in connexion with his researches into venereal diseases. It was announced in 1910 that he had prepared an arsenical compound, known as salvarsan or " 606," which was a cure for syphilis. He lectured in London in 1907, and in 1913 attended the medical congress held there. He received many honours from his Government and marks of distinction from almost every university and scientific society. He died at Homburg Aug. 20 1915.
See Paul Ehrlich: eine Darstellung seines wissenschaftlichen Wirkens, Festschrift zum 60. Geburtstage des Forschers (1914).
EICHHORN, HERMANN VON (1848-1918), German field- marshal, was born at Breslau Feb. 13 1848. He took part, as a young officer, in the campaigns of 1866 and 1870-1. In 1897 he was appointed chief of the staff of the VI. Army Corps at Breslau, in 1901 divisional and in 1907 corps commander. In 1905 he was promoted to the rank of general of the infantry and in 1913 to that of Generaloberst, while in the same year he was appointed inspector-general of the VII. Army Inspection at Saarbriicken. At the outbreak of the World War he was incapacitated in consequence of an accident, but was able to play a part in the battle of Soissons in Jan. 1915. In that month he was appointed to the command of the X. Army, which was engaged in the great battle of the Masurian Lakes in the following February. In Aug. he took Kovno and afterwards the fortresses of Grodno and Olita, and continued his victorious advance into Russia. From 1916-8 Eichhorn was in command of the army group known by his name in Courland. In Dec. 1917 he was raised to the rank of field-marshal and was sent to the Ukraine as chief-in- command of the German troops on the eastern front. He was assassinated at Kiev July 30 1918.
EINEM, KARL VON (1853- ), Prussian general, was born at Hertzberg in the Harz Jan. i 1853. He entered the Prussian army in 1870 and rose to the rank of major-general in 1900. In the same year he was entrusted with the organization of the German section of the international military expedition to Peking. In 1903 he was raised to the rank of lieutenant-general and appointed Minister of War, an office which he held till 1909. He had meanwhile been promoted to be a general of the cavalry, and in 1909 he was placed in command of the VII. Army Corps, which under Kluck he led in the advance through Belgium in 1914. In Sept. 1914 he was appointed to the command of the III. Army (the army of the Aisne), which he successfully handled throughout the heavy fighting in Champagne in Feb. 1915. He continued his defence of his section of the German position with this army throughout 1917 and the early months of 1918.
EINSTEIN, ALBERT (1879- ), German-Swiss physicist, was born of Jewish parents at Ulm in the kingdom of Wiirttemberg on May 14 1879. His boyhood was spent at Munich where his father, who owned electro-technical works, settled in the early 'eighties. The family migrated to Italy in 1894, whilst Albert Einstein went to the Cantonschule at Aarau in Switzerland, where he passed the abiturienten examination, the indispensable preliminary to any professional career in Central Europe, two years later. He attended lectures while supporting himself by teaching mathematics and physics at the polytechnic school at Zurich until 1900 and finally, after a year as tutor at Schaffhausen, was appointed examiner of patents at the patent office at Berne, where, having become a Swiss citizen, he remained until 1909. It was during this period that he took his Ph.D. degree at the university of Zurich and published his first papers on physical subjects. These were so highly thought of that in 1909 he was appointed extraordinary professor of theoretical physics at the university of Zurich. In 1911 he accepted the chair of physics in Prague, only to be induced to return to his own polytechnic school at Zurich as full professor in the following year. In 1914 his preeminence had become so evident that a special position was created for him in Berlin, where he was elected a member of the Royal Academy of Sciences and given a sufficient stipend to enable him to devote all his time to research without any re- strictions or duties whatsoever. He was elected a foreign member of the Royal Society in 1921, having also been made previously a member of the Amsterdam and Copenhagen Academies, while the universities of Geneva, Manchester, Rostock and Princeton conferred honorary degrees on him.
Einstein's work is so important and has proved fertile in so many various branches of physics that it is not possible to do more than enumerate a few of the most salient papers. The work by which he is best known, the theory of relativity, was begun in 1905 with the publication of the restricted principle with its consequences (see RELATIVITY). Though considered fantastic by many, it had secured fairly general acceptance in Germany in 1912, and was fol- lowed by the generalized theory in 1915. But Einstein's work has been by no means confined to such abstract questions. One of his earliest publications gave the complete theory and formulae of the phenomenon known as Brownian motion, which had puzzled physi- cists for nearly 80 years. He showed that the heat motion of particles, which is too small to be perceptible when these particles are large, and which cannot be observed in molecules since these themselves are too small, must be perceptible when the particles are just large enough to be visible and gave complete equations which enable the masses themselves to be deduced from the motions of these particles. Much of his time again was spent on the obscure problems usually combined under the heading " quantum theory." The importance of these has become more and more evident, and the difficulty of reconciling the apparently inevitable discontinuities of the product of energy and time which experiment indicates, with our accepted habits of mind, always had a peculiar fascination for Einstein. Sooner probably than anybody else he realized the far-reaching impli- cations of the theory propounded by Planck. His paper on the varia- tion of the specific heat with temperature, which appeared in 1907, was the first extension of Planck's fuadamental hypothesis, and its verification in essentials is one of the most convincing arguments in its favour. Numerous other papers on molecular physics, including an experimental research on magnetism, appeared in the Proceed- ings of the Russian Academy of Science, the Physikalische Zeit- schrift, the Proceedings of the German Physical Society, the Annalen der Physik, etc. (F. A. L.)
EISNER, KURT (1867-1919), Bavarian Socialist politician and author, was born in Berlin on May 14 1867. He became a journalist, and at an early stage of his career had the first of his many experiences of imprisonment for the subversive tendency of his writings. He was successively on the editorial staff of the Vorwaerts in Berlin 1898-1905 and of other socialist newspapers at Niirnberg and Munich. On the outbreak of the World War he at first seemed to be going to side with the Government, but, after having obtained some private knowledge of the way in which German public opinion had been duped, he turned against his own party, the Social Democrats, and attacked them for supporting the war. In Jan. 1918 he was prosecuted at Munich on a charge of treason for inciting munition workers to strike. He was released from prison on the ground that he was a candidate for the Reichstag, and recovered his liberty in time to arrange the mass meeting on the Theresienwiese at Munich on Nov. 7 1918, which the same day led to the overthrow of the Bavarian monarchy, the flight of the King, and the institution of a Bavarian revolutionary Government under the presidency of Eisner. A red-haired Jew, he possessed a magnetic and artistic temperament, and had various special methods of arousing and restraining the revolutionary masses, including orchestral and vocal concerts of high excellence in the formerly royal theatres and the opera house of Munich. His policy followed extreme lines in the sense of furthering the Workmen's and Soldiers' Councils system, while at the same time he manifested a Bavarian particularism of his own in his efforts to maintain his conceptions of republican government in conjunction with the Councils in Bavaria as against the centralizing tendencies of the Berlin policy. It was with difficulty that he was induced to agree to the arrangements for reestablishing the Federal system of the German Reich and for the election of a National Constituent Assembly. Meanwhile a Bavarian Assembly had been elected, and the Bavarian reactionaries feared that, when it assembled, Eisner's influence might continue to predominate Or might even be fortified. He was, further, obnoxious to them on account of his revelations as to the origin of the war, and at an international Socialist conference at Berne he had urged the German delegates to make a clean breast of Germany's war guilt. He was on his way to open this Assembly, when he was shot dead in the street by a young Count Arco on Feb. 21 1919. This crime was speedily followed by the Bolshevist chaos into which Munich was for a brief period plunged in April.
