HAHNEMANN, hairte-mAn, SAMUEL (1755 1843). The founder of homeopathy. He was born at Meissen, Saxony, the son of a painter of Dres den china. After obtaining a primary education with difficulty, at the age of twenty he left Meis sen, with 20 crowns as his fortune, and went to Leipzig, to prosecute his medical studies. Here he maintained himself by translating works from Latin, French, and English into German. Two years later he went to Vienna, where, under the direction of Dr. Quarin, he pursued his studies, but a year afterwards was obliged to seek funds through employment as physician and librarian at Hermanstadt. He was graduated in medicine from the University of Erlangen in 1779. Sub sequently he retired to Saxony, and settled in Dresden in the year 1784. His attention at this time was given to the study of toxicology of ar senic and of mercury. After spending four years in Dresden, where he had for a time the direction of a large hospital, he returned in the year 1789 to Leipzig. In the following year, while translating Cullen's Materia Medica from English into Ger man, he became interested in the similarity of the effects of quinine and some other drugs upon the healthy body with the result of certain dis eases for which these drugs are used. In other words, he discovered, independently, Hippocrates's old 'law of similars.' With intense interest he searched medical literature for confirmation of his belief in a new principle of cure which he at once began to advocate, namely, that drugs which produce certain symptoms in the healthy body will cure a disease which exhibits similar symp toms. In Hufeland's Journal, in 1796, he pub lished his first important paper, entitled, "An Attempt to find a New Principle for the Discov ery of the Healing Power of Medicine, with Ob servations on Existing Methods." About 1800 he promulgated the principle of `potentization' or `dynamization' of drugs, by trituration of minute amounts of dry drugs with inert material, or dilution and vigorous shaking of minute quan tities of liquid drugs, claiming for such prepara tions increased strength from the new arrange ment of molecules. `Dynamization,' he claimed, imparted a spirit-like force to the dose. In 1810 Hahnemann published his Organon der ration elles Heilkunde, which was translated into many languages, and in which'he expounded his new system, which he called homeopathy. Between 1810
and 1821 he published, at Leipzig, his Materia Medica, under the name Reine Arzneimittellehre, in six volumes. In this work he set forth his observations of the effects of drugs upon healthy people. About the same time he founded at Leip zig a school which soon attracted students from all over the country. In 1828, in his work on chronic diseases, written at K6then, he discussed the disease known as the itch, and reached the conclusion that all diseases are modifications of the itch. The discovery that the itch insect, Sarroptes scabiei (A tarns scabiei), is the cause of scabies beyond' a doubt, caused a change in the belief of homeopathists all over the world, and an abandonment of what had been called the first principle of homeopathy.
As Hahnemann's system involved the admin istration of medicines each separately by itself and in minute doses, there was no longer any need of the apothecary's intervention between the physician and the patient. In consequence of this, the apothecaries' company brought to bear upon Hahnemann an act forbidding physicians to dispense their own medicines, and with such effect that he was obliged to leave Leipzig. The Duke of Anhalt-Kothen appointed him his phy sician, and invited him to live at Kothen. Thith er, accordingly, he removed in the year 1821, and there he prepared various new editions of his Organon and new volumes of his Materia Modica for publication. In 1835 he left Kiithen, and set tled in Paris, where he enjoyed a great reputa tion till his death, which took place in the year 1843. On the centenary of his birth in 1855, a statue was erected to his honor at Leipzig, at the expense of his disciples in Germany, France, England, and other countries, with the concur rence of the local authorities, who supplied the site in one of the public places in their handsome town. His principal work, besides those already mentioned, is Pragmenta de Viribus Medica nzentorunt (1805). Consult his Life and Letters, by Bradford (Philadelphia, 1895). See HOME OPATHY.