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In my view, the Christian religion is the most important and one of the first things in which all children, under a free government ought to be instructed... No truth is more evident to my mind than that the Christian religion must be the basis of any government intended to secure the rights and privileges of a free people. Preface to 1828 Dictionary
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FELD'SPAR,
A name given to a group of
minerals, closely related in crystalline form, and all silicates of
alumina with either potash, soda, lime, or, in one case, baryta. They
occur in crystals and crystalline masses, vitreous in luster, and
breaking rather easily in two directions at right angles to each
other, or nearly so. The colors are usually white or nearly white,
flesh-red, bluish, or greenish.
* The group includes the monoclinic (orthoclastic) species orthoclase or common potash feldspar, and the rare hyalophane or baryta feldspar; also the triclinic species (called in general plagioclase) microcline, like orthoclase a potash feldspar; anorthite or lime feldspar; albite or soda feldspar; also intermediate between the last two species, labradorite, andesine, oligoclase, containing both lime and soda in varying amounts. The feldspars are essential constituents of nearly all crystalline rocks, as granite, gneiss, mica, slate, most kinds of basalt and trachyte, etc. The decomposition of feldspar has yielded a large part of the clay of the soil, also the mineral kaolin, an essential material in the making of fine pottery. Common feldspar is itself largely used for the same purpose. | ||||||||