CAHOURS, AUGUSTE.

Recherches chimiques sur le Salicylate de Méthyléne et L'éther salicylique.

Paris, Fortin, Masson et Cie, 1844. 8vo. Contemp. hcalf, raised bands, gilt spine. Light wear along edges. Small stamps on verso of titlepage. In: "Annales de Chimie et de Physique", 3e Series - Tome 10. 512 pp. a. 5 folded engraved plates (showing experimental apparatus). Small stamp to verso of plates. (The entire volume offered). Cahours' paper pp. 327-369.

First pinting of Cahours' paper on the oil of Gaultheria procumbens.
"Among Cahours’s other accomplishments the most important are the discovery (1834) of toluene, identified among the products of the dry distillation of benzoin, and the study (1844, the paper offered) of the oil of Gaultheria procumbens, known to have the same composition and properties as methyl salicylate; Cahours demonstrated by synthesis that it was the same substance. Cahours also discovered anisic acid, anisole, and the polysulfides of alcohol."(DSB).

The volume contains CHARLES WHEATSTONE "Description de plusieurs Instruments et procédés nouveaux pour déterminer les Constantes d'un Circuit voltaique", pp. 257-298. In this importent paper, here in the first French edition, Wheatstone confirmed experimentally Ohm's Law. "In 1843 Wheatstone published an experimental verification of Ohm’s law, helping to make the law (already well known in Germany) more familier in England. In connection with the verification he developed new ways of measuring resistances and currents. In particular, he invented the rheostat and popularized the Wheatstone bridge, originally invented by Samuel Christie." (DSB).

Order-nr.: 49328