HARMOTOME, a mineral of the zeolite group, consisting of hydrous barium and aluminium silicate, H2BaAl2(SiO3)5 + 5H2O. Usually a small amount of potassium is present replacing part of the barium. The system of crystallization is monoclinic; only complex twinned crystals are known. A common and characteristic form of twinned crystal, such as is represented in the figure, consists of four intercrossing individuals twinned together according to two twin-laws; the compound group resembles a tetragonal crystal with prism and pyramid, but may be distinguished from this by the grooves along the edges of the pseudo-prism. The faces of the crystals are marked by characteristic striations, as indicated in the figure. Twinned crystals of exactly the same kind are also frequent in phillipsite (q.v.). Crystals are usually white and translucent, with a vitreous lustre. The hardness is 4½, and the specific gravity 2.5.
The name harmotome (from ἁρμός, “a joint,” and τέμνειν, “to cut”) was given by R. J. Haüy in 1801, and has a crystallographic signification. Earlier names are cross-stone (Ger. Kreuzstein), ercinite, andreasbergolite and andreolite, the two last being derived from the locality, Andreasberg in the Harz. Morvenite (from Morven in Argyllshire) is the name given to small transparent crystals formerly referred to as phillipsite.
Like other zeolites, harmotome occurs with calcite in the amygdaloidal cavities of volcanic rocks, for example, in the dolerites of Dumbartonshire, and as fine crystals in the agate-lined cavities in the melaphyre of Oberstein in Germany. It also occurs in gneiss, and sometimes in metalliferous veins. At Andreasberg in the Harz it is found in the lead and silver veins; and at Strontian in Argyllshire in lead veins, associated with brewsterite (a strontium and barium zeolite), barytes and calcite.
(L. J. S.)
HARMS, CLAUS (1778-1855), German divine, was born at Fahrstedt in Schleswig-Holstein on the 25th of May 1778, and in his youth worked in his father’s mill. At the university of Kiel he repudiated the prevailing rationalism and under the influence of Schleiermacher became a fervent Evangelical preacher, first at Lunden (1806), and then at Kiel (1816). His trenchant style made him very popular, and he did great service for his cause especially in 1817, when, on the 300th anniversary of the Reformation, he published side by side with Luther’s theses, ninety-five of his own, attacking reason as “the pope of our time” who “dismisses Christ from the altar and throws God’s word from the pulpit.” He also had some fame as a hymn-writer, and besides volumes of sermons published a good book on Pastoraltheologie (1830). He resigned his pastorate on account of blindness in 1849, and died on the 1st of February 1855.
See Autobiography (2nd ed., Kiel, 1852); M. Baumgarten, Ein Denkmal für C. Harms (Brunswick, 1855).
HARNACK, ADOLF (1851- ), German theologian, was born on the 7th of May 1851 at Dorpat, in Russia, where his father, Theodosius Harnack (1817-1889), held a professorship of pastoral theology.