19th century in science Carnot captured some of the ideas of thermodynamics in his discussion of the efficiency of an idealized engine. Sadi Carnot's work provided a basis for the formulation of the first law of thermodynamics—a restatement of the law of conservation of energy—which was stated around 1850 by William Thomson, later known as Lord Kelvin, and Rudolf Clausius. Lord Kelvin, who had extended the concept of absolute zero from gases to all substances in 1848, drew upon the engineering theory of Lazare Carnot, Sadi Carnot, and Émile Clapeyron–as well as the experimentation of James Prescott Joule on the interchangeability of mechanical, chemical,
History of the Jews in 19th-century Poland The Jewish Enlightenment, Haskalah, began to take hold in Poland during the 19th century, stressing secular ideas and values. Champions of Haskalah, the Maskilim, pushed for assimilation and integration into Russian culture. At the same time, there was another school of Jewish thought that emphasized traditional study and a Jewish response to the ethical problems of anti-semitism and persecution, one form of which was the Musar movement. Though the Jews in the Pale were generally poorer and less educated than in other areas, they were still part of the debate over the future of Judaism in the 19th century. By