Blomstrand, Christian Wilhelm

However, the story does not end there. It was not until 1844 when Heinrich Rose (1795-1864) rediscovered the element by producing two similar acids from the mineral niobic acid and pelopic acid. Rose did not reahze he had discovered the old columbium, so he gave this new element the name niobium. Twenty years later, Jean Charles Galissard de Marignac (1817—1894) proved that niobium and tantalum were two distinct elements. Later, the Swedish scientist Christian Wilhelm Blomstrand (1826—1899) isolated and identified the metal niobium from its similar twin, tantalum. 

Whereas Kekule disposed of complex compounds by banishing them to the limbo of molecular compounds , other chemists developed highly elaborate theories to explain their constitution and properties. The most successful and widely accepted of such pre-Werner theories was the chain theory,47 advanced by Christian Wilhelm Blomstrand (1826-1897)4 and developed by Sophus Mads Jorgensen (1837—1914).46 49 50 Although Werner s ideas eventually triumphed, this did not invalidate Jorgensen s observations. On the contrary, his experiments have proven completely reliable and provided the experimental foundation not only for the Blomstrand—Jorgensen chain theory but also for Werner s coordination theory. 

Christian Wilhelm Blomstrand (1826-1897). (Reproduced with permission from reference 10- Copyright 1954 Kemisk Forening.)... 

Christian Wilhelm Blomstrand (1826-1897), Swedish chemist and mineralogist, was professor at Lund University 1862-1895 (3). He gained an intemationsd reputation for his inorganic experimental research and for his accurate analyses of minerals. He was also renowned for his views on the constitution of diazo compounds and metal complexes (coordination compounds), published in German periodicals during the 1870s but already developed in his book Die Chemie der Jetztzeit (Contemporary Chemistry), the 417-page treatise on the theoretical aspects of chemistry, from which Werner took his motto. 

The most successful theory of coordination compounds prior to that of Alfred Werner was advanced in 1869 by Christian Wilhelm Blomstrand (1826-1897) (Figure 12.4). In order to account for the lack of reactivity of ammonia in the ammines, he proposed that chains of ammonia molecules linked the metal atom to other parts of the molecule (Figure 12.5). Blomstrand thereby assigned nitrogen a... 

In 1869 Christian Wilhelm Blomstrand first formulated his chain theory to account for the cobalt ammonate chlorides and other series of ammonates. Blomstrand, knowing that the fixed valence of cobalt was established at 3, chained together cobalt atoms, divalent ammonia groups, and monovalent chlorides to produce a picture of... 

It should be added that other attempts to systematize the elements suffered the same fate. For example, the professor of chemistry in Lund, Christian Wilhelm Blomstrand (1826-97), presented a system of the elements in 1870 in his heavily revised third edition of the much used textbook by Nils Johan Berlin (1812-91). He also discussed this system in his own textbook from 1873 and in a more popular version in 1875. ... 

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