Thermodynamics the work of French physicist Nicolas Léonard Sadi Carnot (1824) who believed that engine efficiency was the key that could help France win the Napoleonic Wars. Scots-Irish physicist Lord Kelvin was the first to formulate a concise definition of thermodynamics in 1854 which stated, "Thermo-dynamics is the subject of the relation of heat to forces acting between contiguous parts of bodies, and the relation of heat to electrical agency." The initial application of thermodynamics to mechanical heat engines was extended early on to the study of chemical compounds and chemical reactions. Chemical thermodynamics studies the nature of the role of
Diseases and epidemics of the 19th century Diseases and epidemics of the 19th century Diseases and epidemics of the 19th century reached epidemic proportions in the case of one emerging infectious disease: cholera. Other important diseases at that time in Europe and other regions included smallpox, typhus and yellow fewer. Epidemics of the 19th century were faced without the medical advances that made 20th-century epidemics much more rare and less lethal. Micro-organisms (viruses and bacteria) had been discovered in the 18th century, but it was not until the late 19th century that the experiments of Lazzaro Spallanzani and Louis Pasteur disproved spontaneous generation conclusively, allowing germ theory