edited b y
JOHN H. WOTlZ Southern Illinois Universih Carbondale. 62901
This column is a series of short articles an the less known events that contributed to important and interesting developments in chemistry. Manuscripts, of about two doublespaced, typewritten pages, and other inquiries should be addressed to the column editor, Dr. John Wotiz, Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, lllinois 62901.
Vitamin BIZ J o h n Webb Research School of Chemistry Australian National Uniuersitv. Canberra, 2600 Australia and Peter Morris University of Waikato Hamilton, New Zealand Vitamin BIZ. the only known vitamin containing a metal ion, cohalt, was first isolated in crystalline form in 1948 by investigators in England and the United States. This success followed 20 years of effort stimulated by the original observation that liver contained a "factor" active in the treatment of patients suffering from pernicious anemia. Isolation of this "factor" was severely hampered by the difficult nature of the assay used to follow the purification, namely, a human bioassay procedure involving the response of patients with pernicious anemia. Today, efforts to elucidate its biochemical role continue; yet the detailed structure of the vitamin in the solid state is known and the total synthesis has been reported recently .z The vitamin is required by all higher animals for growth and for normal blood formation, but animals do not have the ability to synthesize it directly. Instead many animals depend for their dietary supply primarily on microbial synthesis by fermentation in the first part of the stomach, the intestinal rumen. The success of this synthesis depends, in turn, on the availability of a source of cohalt in the feed of these ruminant animals, e.g. sheep and cattle. Disastrous effects follow from a deficient supply of the ~netal.~.~ These effects were first descrihed over 100 years before the isolation of the crystalline vitamin, in 1831, when a disease called "Pine" was descrihed a s affecting sheep in parts of Scotland. Subsequently, similar diseases, e.g. "wastina" disease, "hush sickness." were described in New zealand, ~ u & a l i a , Africa, and America. Characteristics of the disease include loss of appetite, progressive -. emaciation, and a t a later stage, anemia. Farmers of the 19th century soon discovered that grazing on certain well-defined areas induced the disease and that affected animals often completely recovered when transferred to sound areas. Early attempts to understand the cause of this disease, which rendered large areas un~
suitable for farming, focussed on the possibility that the soils might he deficient in iron, the most important dietary trace metal. Eventually, by 1931, one common practice for curing and preventing hush sickness involved the use of a mixture of salt and the hydrated iron oxide mineral, limonite, in " l i c k form to supplement the diet of sheep and cattle. Unfortunately all sources of limonite were not equally useful in this treatment. The important experiment was soon carried out. An extract of potent limonite was prepared which had been leached free of iron yet was effective in curing wasting disease. Soon after, in 1934-5, investigators unamhiguously showed that cohalt cured the disease and was, in fact, the active component in lmonite. Applications of cohalt to affected soils, usually as cobalt sulfate in superphosphate topdressing, revitalized the land and rendered it suitable once more for grazing. This nutritional phenomenon provided a clear example of dietary deficiency of cobalt in animals. Ironically, the human disease of pernicious anemia, which had stimulated biochemists to the eventual isolation of vitamin BIZ, the cobalt-containing vitamin whose deficiency gives rise to wasting disease in sheep and cattle, is not caused by a lack of dietary cobalt or vitamin BIZ.Rather, pernicious anemia results from defective secretion in the gastric juices of a factor that is required for successful absorption of ingested vitamin BIZ, unless the vitamin is given in enormous excess. White, A,, Handler, P., and Smith, E. L., "Principles of Biochemistry," 3rd Ed.. McGraw-Hill,New York, 1964, p. 9 6 i . .Scicnrc 179.26fi-7 (1973). "Cobalt Deficiency in Sheep and Cattle," Bulletin No. 183, New Zealand Department of Agriculture. Andrews, E. D., New Zeoiond Journal of Az~i'ricultur~, 92, 219244 (1955).
Berzelius and the Discovery of Thorium William H. W a m o n e r Uniuersity of Georcia Athpns. Geor~in30602 Jhns Jacob ~ e r z e l i u s(i779-1848) is generally considered to have been one of the 19th centurv's . .areatest chemists. In addition to his extensive investigations of minerals, his electrochemical researches led to the formulation of the Dualistic Theory, to nomenclature reforms, and to the introduction of the notation system still used by chemists today. Deeply involved with the concept of atomism, his systematic study of combining weights contributed significantly to the store of experimental data which estahlished the atomic theory as one of the fundamental ideas of chemical science. Berzelius discovered three new chemical elements: cerium (1803). selenium (1817). and thorium (1828). In addition to these recognized discoveries, he advanced two Volume 52, Number 1, January 1975
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abortive claims. The first of these was put forth in 1803, shortly after the announcement of cerium, when he was not yet 25 years old ( I ) . "In his enthusiasm, Berzelius believed he had found yet another new element. In honor of Johan Gottlieb Gahn (1745-1818). the berg-master in Falun, . . . he called it Gahnium. This, however, proved to he zinc oxide." In 1815, Berzelius claimed (2) to have obtained a peculiar substance from a sample of gadolinite from Koroufvet. This new substance differed from other earths in its properties hut because it was detected in only one of the analyses, and only a small quantity was available, he decided not to include it in his published results until its existence could he demonstrated more conclusively. During the next year, Berzelius continued his examination of unusual Swedish minerals and reported (3) on the composition of several new ones. This work was finally collected into a single article which was published in the fifth volume of Afhandlingar i Fysik, Kemi och Mineralogi, a journal edited by Berzelius and William Hising (1766-1852), later Baron von Hisinger. This article carried the names of Gahn, Berzelius, Wallman, and Eggertz as coauthors and dealt with the analyses of eight minerals found in the vicinity of the village of Fahlun (Falun), Sweden. In two of the minerals examined, a new earth was detected which proved to he identical with that obtained from gadolinite the preceding year. A variety of reactions was reported to establish the individuality of this new earth and in recognition of the fact that many of the experiments had been conducted in Gahn's laboratory at Fahlun, Benelius suggested the name "thorine" for it, deriving this term from the name of the ancient Scandinavian god, Thor. In the German extract of this article, however, Editor Ludwig Wilhelm Gilbert (1769-1824) suggested (41 that "the suffix -ine is not appropriate for an earth and that it should he named thorina or thora, by analogy with silica, alumina, and magnesia.'' The true nature of thorine was established in 1824 by Berzelius himself in connection with his researches (5) on fluorides. The following year, a "Note on Thorine" was appended (6) to a paper on zirconium. Here Berzelius admitted that his subsequent experiments had convinced him that his earlier conclusions had been erroneous. "As a result of that research, the substance which I have described under the name thorine is nothing but the subphosphate of yttria." Not one to let a good name go to waste, however, Berzelius again chose to honor Thor when he did discover the element now called thorium (7) in 1828. But an interesting postscript can be added. Despite his retraction, Berzelius' misidentification was not forgotten by everyone for it subsequently was associated wth another misnomer which has persisted. The mineral in which the recognized element was found is known as thorite, although the suggestion was made at the time that it be called berzelite. Ideally, it is the ortho-silicate of thorium. The mineral involved in the 1815 investigation, later identified as yttrium phosphate, is now called xenotime. This name is due to the French mineralogist, Francois Sulpice Beudant (1787-1850). but spelled in this manner, it is a misprint of his original proposal. As he later stated (8).the name was supposed to be kenotime derived from the Greek KC"&, vain, and T L F ~ honor, , and was intended to recall the fact that in 1815 Berzelius had made a mistake in claiming that it contained a new metal. Whatever the irony thus introduced by an unknown typesetter's misspelling, Berzelius might well have had the last laugh for thorium is found as a vicarious constituent in xenotime in quantities up to 2.5%. Literature Cited (11 Jome,. .I. E.. "Jac Benelius. His Life and Work." i T m s i a t o r stee1e. 5.1. Almqvist and Wihell. Stoekhoim. 1966. p. 29.
(21 Gahn. J. G.. Berzeliu~.J . J.. Wallman. C. A,. and Emrtz. H. P., A m . Chim.
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