# Popular Science Monthly/Volume 31/June 1887/Sketch of Jules Jamin

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JULES JAMIN.
* SKETCH OF JULES JAMIN.
M. JULES JAMIN was a man of many talents. He held a high position in the scientific circles of his time, and was equally eminent as a teacher and lecturer; he was also well known in literature; and he achieved respectable success in some of the fine arts. He was able to acquit himself creditably in all this variety in occupations, without sacrificing the excellence of his scientific work; and it is on the last that his fame is founded.
Jules Célestin Jamin was born at Termes in the Ardennes, August 30, 1818, and died in Paris, February 12, 1886. His father had served in the volunteers of the French Revolution, had gained the rank of captain, and had been decorated at the battle of Friedland. The boy was taught in the village school of Vouziers, and afterward in the college at Rheims, where he gained nine prizes in the first year, and received in 1838 the prize of honor in the competition between the colleges of Paris and the departments. In the same year he entered the Superior Normal School, and in 1841 received the first prize in the examinations of physics. From this institution he went to the college at Caen as a teacher of Physics; afterward to the Collége Bourbon (now Lycée Condorcet), and in 1844 to the Collége Louis-le-Grand. In 1847 he received the doctorate of Physical Science for a thesis on the reflection of light by the surface of metals.
The precision, elegance, and solidity of his instruction, say Jamin's foreign biographers, and the value of his scientific work, designated him for some superior professorship. So, in 1852, he was elected Professor of Physics at the Polytechnic School, where he lectured with success till 1881. In 1863 he obtained the chair of Physics in the Faculty of Sciences, where, by the extreme lucidity of his demonstrations, he achieved a great success. When M. Duruy, the Minister of Instruction at the time, founded the public lectures of the Sorbonne, he committed the inauguration of the course to M. Jamin; and the opening was, according to M. Jurien de la Gravière's eulogy in the Academy of Sciences, an event which "aroused the enthusiasm of the multitude." Here Jamin attracted a great number of eager listeners, and displayed, says "Nature," his admirable talent of exposition, as well as his great power of simplifying the most difficult questions, ​and of indicating by most striking apparatus the methods of solving many intricate problems. The qualities that Jamin displayed in his oral teaching are found in his "Traité Général de Physique," which reproduces his course at the Polytechnic School, and "in which masters as well as pupils find exact descriptions of the actual state of science." This work was published 1858 to 1861, in three volumes.
M. Jamin was elected to the Section of Physics in the Academy of Sciences in 1868. In 1884 he was chosen perpetual secretary in the place of Dumas. His address on the anniversary of the admission of M. Dumas to the Academy was regarded as a rare example of pathetic eloquence; and in 1885 he delivered an address on the occasion of the centenary of M. Arago, which was characterized by its philosophical examination of the labors of that distinguished experimenter, and its thoughtful analysis of his mental powers, as well as by the clearness with which these points were presented.
M. Jamin's labors were carried on in very diverse branches of physics; and he interested himself and became versed in other departments of science and art. While studying for the degree in Physics at the Normal School, he also qualified himself for a degree in Natural Sciences. At Caen he took geological and botanical excursions with his pupils on Sundays. Of his regular studies he was first occupied with optics. His first memoir, already spoken of, on the reflection of light from metallic surfaces, was in this line, and was one of the best studies of the kind. Others were his studies of interferences, and of the measurement of the indices of refraction, of gases, of water under different pressures, and of the vapor of water. He discovered the elliptical polarization of light reflected by vitreous substances near the polarizing angle, and the negative elliptical polarization of fluorine; he published a memoir on colored rings, and invented interference apparatus in which the light reflected on opposed faces of thick transparent rings was utilized. He made discoveries in capillarity. In 1873 he exhibited a foliated magnet which was capable of carrying twenty-two times its own weight, while the greatest carrying power attained by artificial magnets previous to that time had been from four to five times their weight. This result was obtained by substituting, for the thick plate hitherto employed, a sufficient number of very thin plates superposed on each other, and all thoroughly magnetized. In these and other experiments in electrical science M. Jamin was greatly assisted by the research laboratory which M. Duruy had endowed. Among the later fruits of these researches was the perfection of the Jamin electric light, as an improvement upon the Jablochkoff candle. In his description of this lamp, the inventor sums up its qualities by saying: "It lights and relights itself as often as is required; it only requires one circuit for all the neighboring candles; it replaces automatically those which are entirely consumed, by new carbons; it employs no insulating material which might alter the color of the ​flame; and it requires no preliminary preparation of the carbons, which considerably diminishes the expense." The credit of a simultaneous application of the most important principle of this invention has been claimed for Mr. Robert Sabine. Besides these subjects, M. Jamin applied his researches to the compressibility of liquids; hygrometry, on which he was engaged at the time of his death; specific heats; and the critical points of gases. A paper of his on the "Liquefaction of the Elementary Gases," in which the last subject was brought into bearing, was published in "The Popular Science Monthly" for December, 1884."By their historical order and succession," says "Nature," "his memoirs indicate the progress of physics in France since the middle of the century to the present day." In literature he was one of the regular contributors to the "Revue des Deux Mondes"; and in the earlier editions of the cyclopædias in which his name is given, these articles are mentioned, along with the "Traité de Physique," as the works by which he was chiefly entitled to distinction. He had taste and skill in music. He was a painter of considerable artistic talent, fond of studying the works of the great masters at the Louvre; and was the executor of "an admirable portrait of Lefebvre," of a picture which is preserved in the church in his native village, and of several paintings which are in the possession of his family.
A neat picture of the versatility of his tastes and of his social qualities is given in the sketch of him in "La Nature" and "Nature": "It was only on his return to Paris from Caen that his great power, elevated ideas, distinguished tastes, and fine intelligence could find a free scope. He remembered always with pleasure how at the age of twenty-five he found himself at once surrounded by an intelligent and enlightened society. He dined in a pension with several of his colleagues, who have left names either in science or at the university; with Lefebvre, the eminent professor at the Collége Rollin, with Saisset, Barni, Suchet, La Provostaye; with Faurie, who often brought his friend Sturm. The dinner was followed by long chats, with dissertations on science, philosophy, music, and art, in which Jamin took an active part." He was esteemed by all who knew him, scientific men and others, at home and abroad, for many other qualities as well as for his scientific attainments. "Cruelly touched by family affliction," says his biographer, "he found in the midst of his workers who needed continually his aid and assistance, some relief for his great grief. During some time before his death he seemed to have mastered his sorrows, and to have regained his usual activity." He had replaced Milne-Edwards as Dean of the Faculty of Sciences, and at the time of his death was at the height of his reputation. His death came from heart-disease, after an illness of six months.