others escaped into exile. He was, however, murdered in 1885 and was succeeded by his nephew Sir Shamsher Jung, G.C.S.I., who died in 1901 and was succeeded by his brother Deb Shamsher Jung. But in June of that year a palace revolution placed another brother, Chandra Shamsher Jung, in power, whilst Deb Shamsher fled to India. Maharajah Chandra Shamsher has ruled Nepal with much ability. He gave effective aid to the British during the Tibet war of 1904, and the relations with the government of India became more cordial after his accession to power. In 1906 Chandra Shamsher was created a G.C.S.I., and in 1908 he visited England as a guest of the government, when he was invested with the G.C.B. by King Edward VII. He was also made a major-general in the British army, and honorary colonel of the 4th Gurkha Rifles.
For authorities see Dr Daniel Wright, History of Nepal (1877); Colonel Kirkpatrick, Account of Nepal; Brian Houghton Hodgson’s essays; Dr H. A. Oldfield’s sketches; Sir C. M. Aitchison, Treaties and Engagements; Sir Joseph Hooker’s writings; and Sir Richard Temple, Hyderabad and Nepal (1887). (D. Wr.; H. Wy.)
NEPENTHES (Gr. νηπενθές, sc. φάρμακον, a drug that takes away grief, from νη- privative, and πένθος, “grief”), an Egyptian drug spoken of by Homer in the Odyssey (iv. 221). Generally in the form “nepenthe” the name is given to any drug having a like property, and also occasionally to the herb or plant from which such a drug is produced. It is also applied to a special genus of plants, chiefly East Indian, known as the “pitcher-plants,” on account of the formation of the leaves.
NEPHELINE, a rock-forming mineral consisting of sodium, potassium and aluminium silicate, Na6K2Al8Si9O34. Its crystals belong to the hexagonal system, and usually have the form of a short six-sided prism terminated by the basal plane. The unsymmetrical etched figures produced artificially on the prism faces indicate, however, that the crystals are hemimorphic and tetartohedral, the only element of symmetry being a polar hexad axis. The hardness is 512. The specific gravity (2·6), the low index of refraction and the feeble double refraction are nearly the same as in quartz; but since in nepheline the sign of the double refraction is negative, whilst in quartz it is positive, the two minerals are readily distinguished under the microscope. An important determinative character of nepheline is the ease with which it is decomposed by hydrochloric acid, with separation of gelatinous silica (which may be readily stained by colouring matters) and cubes of salt. A clear crystal of nepheline when immersed in acid becomes for this reason cloudy; hence the name nepheline, proposed by R. J. Haüy in 1801, from Gr. νεφέλη, a cloud.
Although in naturally occurring nepheline sodium and potassium are always present in approximately the atomic ratio 3:1, artificially prepared crystals have the composition NaAlSiO4; the corresponding potassium compound, KAlSiO4, which is the mineral kaliophilite, has also been prepared artificially. It has therefore been suggested that the orthosilicate formula, (NaK)AlSiO4, represents the true composition of nepheline.
The mineral is one specially liable to alteration, and in the laboratory various substitution products of nepheline have been prepared. In nature it is frequently altered to zeolites (especially natrolite), sodalite, kaolin, or compact muscovite. Gieseckite and liebenerite are pseudomorphs.
Two varieties of nepheline are distinguished, differing in their external appearance and in their mode of occurrence, being analogous in these respects to sanidine or glassy orthoclase and common orthoclase respectively. “Glassy nepheline” has the form of small, colourless, transparent crystals and grains with a vitreous lustre. It is characteristic of the later volcanic rocks rich in alkalis, such as phonolite, nepheline-basalt, leucite-basalt, &c., and also of certain dike-rocks, such as tinguaite. The best crystals are those which occur with mica, sanidine, garnet, &c., in the crystal-lined cavities of the ejected blocks of Monte Somma, Vesuvius. The other variety, known as elaeolite, occurs as large, rough crystals, or more often as irregular masses, which have a greasy lustre and are opaque, or at most translucent, with a reddish, greenish, brownish or grey colour. It forms an essential constituent of certain alkaline plutonic rocks of the nepheline-syenite series, which are typically developed in southern Norway.
The colour and greasy lustre of elaeolite (a name given by M. H. Klaproth in 1809, from Gr. ἔλαίον, oil, and λίθος, stone; Ger. Fettstein) are due to the presence of numerous microscopic enclosures of other minerals, possibly augite or hornblende. These enclosures sometimes give rise to a chatoyant effect like that of cat’s-eye and cymophane; and elaeolite when of a good green or red colour and showing a distinct band of light is sometimes cut as a gem-stone with a convex surface.
Closely allied to nepheline, and occurring with it in some nepheline-syenites, is the species cancrinite, which has the composition H6Na4Ca(NaCO3)2Al3(SiO4)9. It is frequently of a bright yellow colour, and has sometimes been cut as a gemstone. (L. J. S.)
NEPHELINE-SYENITE, or Elaeolite-syenite, a holocrystalline plutonic rock which consists largely of nepheline and alkali felspar. The rocks are mostly pale coloured, grey or pink, and in general appearance they are not unlike granites, but dark green varieties are also known. They do not contain quartz, as that mineral and nepheline are mutually exclusive. From ordinary syenites they are distinguished not only by the presence of nepheline but also by the occurrence of many other minerals rich in alkalis or in rare earths. Orthoclase and albite are the principal felspars; usually they are intergrown to form perthite. In some rocks the potash felspar, in others the soda felspar predominates. Soda-lime felspars such as oligoclase and andesine are rare or entirely absent. Fresh clear microcline is very characteristic of some types of nepheline-syenite. Sodalite, colourless and transparent in the slides, but frequently pale blue in the hand specimens, is the principal felspathoid mineral in addition to nepheline. As a rule these two crystallize before felspar, but they may occur in perthitic intergrowth with it. The commonest ferro-magnesian mineral is pale green augite, which may be surrounded by rims of dark-green, pleochroic soda-augite (aegirine). The latter forms long flat prisms or bundles of radiating needles. A dark reddish-brown biotite is very common in some of these rocks and a white mica, probably not muscovite but lepidolite, is occasionally present. The hornblende may be brown, brownish-green, blue or blue-black, belonging as a rule to the varieties which contain soda; it is often intergrown with the pyroxene or enclosed in it. The dark-brown triclinic hornblende aenigmatite occurs also in these rocks. Olivine is rare, but may be found in some basic forms of nepheline-syenite.
The commonest accessories are sphene, zircon, iron ores and apatite. Cancrinite occurs in several nepheline-syenites; in others there is fluor-spar or melanite garnet. A great number of interesting and rare minerals have been recorded from nepheline-syenites and the pegmatite veins which intersect them. Among these we may mention eudialyte, eukolite, mosandrite, rinkite, johnstrupite, lavenite, hiortdahlite, perofskite and lamprophyllite. Many of these contain fluorine and the rare earths.
Nepheline-syenites are rare rocks; there is only one occurrence in Great Britain and one in France and Portugal. They are known also in Bohemia and in several places in Norway, Sweden and Finland. In America these rocks have been found in Texas, Arkansas and Massachussetts, also in Ontario, British Columbia and Brazil. South Africa, Madagascar, India, Tasmania, Timor and Turkestan are other localities for the rocks of this series. They exhibit also a remarkable individuality as each occurrence has its own special features; moreover a variety of types characterizes each occurrence, as these rocks are very variable. For these reasons, together with the numerous rare minerals they contain, they have attracted a great deal of attention from petrographers.
Many types of nepheline-syenite have received designations derived from the localities in which they were discovered. The laurdalites (from Laurdal in Norway) are grey or pinkish, and in many ways closely resemble the laurvikites of southern Norway, with which they occur. They contain anorthoclase felspars of lozenge-shaped forms, biotite or greenish augite, much apatite and sometimes olivine. Some of these rocks are porphyritic. The
