MARIGNAC, C. (JEAN CHARLES). - FIRST SEPARATION OF COLUMBIUM AND TANTALIUM.

Recherches sur les Combinaisons du Niobium.

Paris, Victor Masson et Fils, 1866. 8vo. Contemp. hcalf, raised bands, gilt spine. Light wear along edges. Small stamps on verso of titlepage. In: "Annales de Chimie et de Physique", 4e Series - Tome VIII. 512 pp. a. 3 folded engraved plates. (The entire volume offered). Marignac's paper: pp. 5-75.

The paper describes his successfull separation of tantalum and columbium, "and he also shows that columbium is both tri- and pentavalent, whereas tantalum always has a valency of five. The separation is based on the insolubility of potassium fluo-oxyycolumbate." (Weeks p. 83).

Order-nr.: 45989