304 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



gave to Chemistry its nomenclature, died by the guillotine during the 

 French Revolution. A large majcn-ity of the chemical elements were dis- 

 covered during the present century. The list of eminent experimental 

 chemists is too long to be repeated here. In Inorganic Chemistry the name 

 of Berzeliiis stands most prominent; in Organic, that of Liebig. 



The history of Electricity commences with the discoveries of Benjamin 

 Franklin. The law of electric force was demonstrated by Coulomb in 1185. 

 The same philosopher investigated the forces of magnetism. In 1824, 

 Poisson found the formulas for expressing the attractions and repulsions 

 of bodies of any form magnetized by influence on a given point. Galvanism 

 originated in 1791. Volta discovered, in 1794, that the force manifested 

 in Galvani's celebrated experiment was not animal electricity. In 1800 he 

 constructed the Voltaic pile. 



The sciences of Electro-Magnetism had its origin with the discovery of 

 Oersted of Copenhagen, in 1820; and in the same year Ampere solved the 

 general problem of electro-dynamic action. Diamagnetic action was dis- 

 covered by M. le Baillie in 1829. The brilliant experiments of Henry, 

 Saxton, and Farada}', of our own time, are well known. 



To Acoustics LapUice made tlie most important addition in 1816, by the 

 true solution of the problem of the propagation of sound. 



In 1808, Mains discovered the polarization of light. In 1821, Fresnel 

 confirmed the undulatory theory first propounded by Hu^^gens, but went 

 further and demonstrated that light is produced by the transverse vibra- 

 tions of an ethereal medium. The emission tiieory of Newton was finally 

 disproved bj'' the experiments of Fizeau and Foucault, in 1850. 



Benjamin Thompson, an Am(!rican, better known as Count Rumford, 

 proved by experiments at Munich, towards the close of the last century, 

 that heat was the result of motion. In 1817, Dulong and Petit corrected 

 the assumption of Newt<jn, by discovering the true law of cooling. They 

 afterwards made known the relation between the specific heat of elements 

 and their equivalent weight. In 1830, Melloni and Nobilli constructed the 

 thermomultiplier, by means of which the refraction and polarization of 

 heat were demonstrated. The mechanical equivalent of heat was correctly 

 ascertained and announced in 1842, by Dr. J. R. Meyer. 



In Zoology, the methods of Cuvier and Bichat have been followed with 

 brilliant results. The most remarkable discovery, after the commence- 

 ment of the present century', was that of Oken in 1807 — the resolution of 

 the skull into vertebrae. Thirty years later, Agassiz, by a study of tissues, 

 made valuable contributions to the department of Ichthyology. 



In Botati}'^, a very important generalization was made by Jusseieu, in 

 1789, connecting the cotyledon with the endogenous and exogenous gr(nvth 

 of a plant, and its fruit and leaves. A year later Goethe announced the 

 discovery of the law relating the flower to the leaf by arrested develop- 

 ment. At the time of Linnaaus, only 8,000 species were known. In 1849, 

 Balfour states the number then known at about 100,000. During the latter 

 part of the last century, Ilauy established the d(jctrine of decrements in 

 Crystallography, In 1822, the law of Isomorphism was demonstrated by 

 Mitscherlich. 



