De opvattingen van Gay-Lussac over de soortelijke warmte van gassen en de betekenis ervan voor de ontwikkeling van de thermodynamica

Abstract

SUMMARY: In 1845 Joule described his well-known experiment about the expansion of air without work. However, the first who carried out this experiment, which played an important role in the history of early thermodynamics, was Gay-Lussac (1807). In this article a survey is given of the experiments and ideas of Gay-Lussac about the specific heat of gases, as well as a summary of the significance of his experiment in the determination of the mechanical euivalent of heat. Gay-Lussac based himself on the assumption of Dalton (1800), that by measuring the heat effects by the adiabatic expansion of gases it is possible to determine the specific heat of gases. From his experiments. Gay-Lussac concluded that the specific heat of gases is inversely proportional to their specific gravities. Later he stated that the specific heat of all gases has the same value (1812), but afterwards he came to the right conclusion that this is untrue. The conclusion of Gay-Lussac in the year 1807 that, when air rushes from one globe into a vacuous globe, the decrease in temperature in the first globe was equal to the increase in the second, is the greater part of Gay-Lussac's work in the area of thermodynamics. Carnot used this conclusion against the caloric theory of heat and Mayer used it for his classic calculation of the mechanical equivalent of heat. In the priority quarrel between Joule en Mayer, the experiment of Gay-Lussac decides for the former.