DUMAS, JEAN BAPTISTE & ANDRE & J.S. STAS. - THE ATOMIC WEIGHT OF CARBON ESTABLISHED.

Recherches sur la véritable poids atomiques du carbone.(Extrait).

(Paris, Bachelier), 1840. 4to. No wrappers. In: "Comptes Rendus Hebdomadaires des Séances de L'Academie des Sciences", Tome XI , No 25. Pp. (991-) 1020. (Entire issue offered). The paper: pp. (991-) 1008. A bit of marginal soiling and some creasing to leaves.

First appearance of the paper which states the correct weight of the carbon atom. This research had profound influence on the development of organic chemistry. The paper in full was published the year after (1841) in "Annales de Chimie et de Physique".

"From 1840 onward he carried out an important revision of the atomic weights of thirty elements. His most valuable contribution in this field was his very precise determination of the atomic weight of carbon (jointly with his pupil Stas) in 1840. A previously accepted weight, determined by Berzelius as C = 12.20 (O = 16), was shown to be incorrect. Dumas proved that C = 12±.002 (O = 16) or C = 75 (O = 100). The analysis was made by burning diamond and artificial and natural graphite in oxygen; the carbon dioxide formed was weighed in potash solution. The results were in close agreement. The "new" weight of carbon had a great effect on the progress of organic chemistry."(DSB).

Order-nr.: 47238