DELAROCHE, François and Jacques Etienne BÉRARD.
Mémoire sur la détermination de la chaleur spécifique des différens gaz. Extrait des Annales de Chimie; février 1813.
[Paris:] H. Perronneau…1813
8vo, 2 leaves, 115 pages, 2 folding letterpress tables and 2 folding engraved plates of apparatus. Modern boards, original upper wrapper bound in, uncut and largely unopened. Half-title a bit creased and dust-soiled, some minor dust-soiling in margins. Presentation copy, inscribed on the upper wrapper “A Monsieur Professeur Prevost de la part de F. Delaroche.” Pierre Prévost (1751–1839) was a Swiss physicist and philosopher, particularly noted for his work on radiated heat.
FIRST SEPARATE EDITION. In this prize-winning memoir Delaroche and Bérard suggested that there was a simple relationship between the specific heat of a compound gas and its chemical composition. To compare the specific heat of gases, they passed them through a spiral tube immersed in a copper calorimeter filled with water. The rise in temperature of the water when a current of hot gas under constant pressure was passed through the spiral was taken to be proportional to the specific heat. Their method was essentially that used earlier by Lavoisier who is often quoted. Their measurement of the specific heat of gases disproved Crawford’s theory of combustion. Roberts & Trent, Bibliotheca mechanica, pp. 199–200 (this copy).