De Mémoire sur la détermination de la chaleur spécifique des différens gaz (I) WITH Du Mémoire sur la détermination de la chaleur spécifique des différens gaz (II) WITH Sur un Mémoire de M. Bérard relatif aux propriétés physiques et chimiques des divers rayons qui composent la lumière solaire (III) in Annales de Chimie et de Physique, Vol. 85-86, 1813, pp. 72-110, 113-182, and 309-325

Paris: Chez Klostermann, 1813. 1st Edition. BOUND FIRST EDITION OF THREE 1813 WORKS BY DELAROCHE AND BÉRARD THAT TOGETHER ESTABLISHED THE FIRST PRECISE MEASUREMENTS OF THE HEAT CAPACITIES OF GASES & established beyond argument that the specific heats of various gases differ from each other. All three papers are noted in the Dictionary of Scientific Biography as important original works.

Prior to 1812, the state of specific-heat measurements had yet to be established and the need to do so was well understood. The First Class (Mathematical and Physical Sciences) of the French Institute sponsored a prize competition with the goal of moving the state of specific-heat measurements beyond these initial attempts.

"The competition was won by Fran ois Delaroche (1775-1813) and Jacques-Étienne Bérard (1789-1869). They used a constant flow method which involved passing a heated gas under a constant pressure through a spiral copper tube immersed in a calorimeter filled with water. From the amount of heat imparted to the water in unit time and the rate of flow of the gas, Delaroche and Bérard were able to calculate the specific heats (by volume) of various gases under constant pressure.

"This ingenious method, along with the care they took in eliminating the sources of heat loss, won Delaroche and Bérard wide acclaim, and their results on the specific heat of various gases were considered the best available for several decades. Their work established beyond doubt that the specific heats of various gases were different from each other, the volumetric specific heats ranging from 0.903 for hydrogen to 1.258 for carbon dioxide (taking that of atmospheric air as 1)" (Buchwald, Oxford Handbook of the History of Physics, 480). CONDITION & DETAILS: Paris: Chez Klostermann. Volumes 85 and 86, bound as one. Ex-libris with NO spine markings and minimal interior markings (small stamp on title page, blank front flyleaf). 8vo. 8.25 x 5.5 inches (206 x 137mm). 3 plates. Tightly and very solidly bound in maroon cloth with a gilt-lettered spine; minor scuffing to the edge tips. The title page is clipped horizontally at the head about .25 inches in width and not impacting any text. Moderate foxing throughout, largely minor. Very good condition.