Chapter V: Part 5

Two propylene glycols, C3H8O2, are known, viz. [alpha]-propylene
glycol, CH3.CH(OH).CH2OH, a liquid boiling at 188 deg. to 189 deg.,
and obtained by heating glycerin with sodium hydroxide and distilling
the mixture; and trimethylene glycol, CH2OH.CH2.CH2OH, a liquid
boiling at 214 deg. C. and prepared by boiling trimethylene bromide
with potash solution (A. Zander, _Ann._, 1882, 214, p. 178).

GLYCONIC (from Glycon, a Greek lyric poet), a form of verse, best known in Catullus and Horace (usually in the catalectic variety _ [u_] _ u u _ u [u_]), with three feet--a spondee and two dactyls; or four--three trochees and a dactyl, or a dactyl and three chorees. Sir R. Jebb pointed out that the last form might be varied by placing the dactyl second or third, and according to its place this verse was called a First, Second or Third Glyconic.

Cf. J. W. White, in _Classical Quarterly_ (Oct. 1909).

GLYPH (from Gr. [Greek: glyphein], to carve), in architecture, a vertical channel in a frieze (see TRIGLYPH).

GLYPTODON (Greek for "fluted-tooth"), a name applied by Sir R. Owen to the typical representative of a group of gigantic, armadillo-like, South American, extinct Edentata, characterized by having the carapace composed of a solid piece (formed by the union of a multitude of bony dermal plates) without any movable rings. The facial portion of the skull is very short; a long process of the maxillary bone descends from the anterior part of the zygomatic arch; and the ascending ramus of the mandible is remarkably high. The teeth, 8/8 in the later species, are much alike, having two deep grooves or flutings on each side, so as to divide them into three distinct lobes (fig.). They are very tall and grew throughout life. The vertebral column is almost entirely welded into a solid tube, but there is a complex joint at the base of the neck, to allow the head being retracted within the carapace. The limbs are very strong, and the feet short and broad, resembling externally those of an elephant or tortoise.

Glyptodonts constitute a family, the _Glyptodontidae_, whose position
is next to the armadillos (_Dasypodidae_); the group being represented
by a number of generic types. The Pleistocene forms, whose remains
occur abundantly in the silt of the Buenos Aires pampas, are by far
the largest, the skull and tail-sheath in some instances having a
length of from 12 to 16 ft. In _Glyptodon_ (with which
_Schistopleurum_ is identical) the tail-sheath consists of a series of
coronet-like rings, gradually diminishing in diameter from base to
tip. _Daedicurus_, in which the tail-sheath is in the form of a huge
solid club, is the largest member of the family, in _Panochthus_ and
_Sclerocalyptus_ (_Hoplophorus_) the tail-sheath consists basally of a
small number of smooth rings, and terminally of a tube. In some
specimens of these genera the horny shields covering the bony scutes
of the carapace have been preserved, and since the foramina, which
often pierce the latter, stop short of the former, it is evident that
these were for the passage of blood-vessels and not receptacles for
bristles. In the early Pleistocene epoch, when South America became
connected with North America, some of the glyptodonts found their way
into the latter continent. Among these northern forms some from Texas
and Florida have been referred to _Glyptodon_. One large species from
Texas has, however, been made the type of a separate genus, under the
name of _Glyptotherium texanum_. In some respects it shows affinity
with _Panochthus_, although in the simple structure of the tail-sheath
it recalls the undermentioned _Propalaeohoplophorus_. All the above
are of Pleistocene and perhaps Pliocene age, but in the Santa Cruz
beds of Patagonia there occur the two curious genera
_Propalaeohoplophorus_ and _Peltephilus_, the former of which is a
primitive and generalized type of glyptodont, while the latter seems
to come nearer to the armadillos. Both are represented by species of
comparatively small size. In _Propalaeohoplophorus_ the scutes of the
carapace, which are less deeply sculptured than in the larger
glyptodonts, are arranged in distinct transverse rows, in three of
which they partially overlap near the border of the carapace after the
fashion of the armadillos. The skull and limb-bones exhibit several
features met with in the latter, and the vertebrae of the back are not
welded into a continuous tube. There are eight pairs of teeth, the
first four of which are simpler than the rest, and may perhaps
therefore be regarded as premolars. More remarkable is _Peltephilus_,
on account of the fact that the teeth, which are simple, with a
chevron-shaped section, form a continuous series from the front of the
jaw backwards, the number of pairs being seven. Accordingly, a
modification of the character, even of the true Edentata, as given in
the earlier article, is rendered necessary. The head bears a pair of
horn-like scutes, and the scutes of the carapace and tail, which are
loosely opposed or slightly overlapping, form a number of transverse
rows.

LITERATURE.--R. Lydekker, "The Extinct Edentates of Argentina," _An.
Mus. La Plata_--_Pal. Argent._ vol. iii. p. 2 (1904); H. F. Osborn,
"'Glyptotherium texanum,' a Glyptodont from the Lower Pleistocene of
Texas," _Bull. Amer. Mus._, vol. xvii. p. 491 (1903); W. B. Scott,
"Mammalia of the Santa Cruz Beds--Edentata," _Rep. Princeton Exped. to
Patagonia_, vol. v. (1903-1904). (R. L.*)

GLYPTOTHEK (from Gr. [Greek: glyptos], carved, and [Greek: theke], a place of storage), an architectural term given to a gallery for the exhibition of sculpture, and first employed at Munich, where it was built to exhibit the sculptures from the temple of Aegina.

GMELIN, the name of several distinguished German scientists, of a Tubingen family. Johann Georg Gmelin (1674-1728), an apothecary in Tubingen, and an accomplished chemist for the times in which he lived, had three sons. The first, Johann Conrad (1702-1759), was an apothecary and surgeon in Tubingen. The second, Johann Georg (1709-1755), was appointed professor of chemistry and natural history in St Petersburg in 1731, and from 1733 to 1743 was engaged in travelling through Siberia. The fruits of his journey were _Flora Sibirica_ (4 vols., 1749-1750) and _Reisen durch Sibirien_ (4 vols., 1753). He ended his days as professor of medicine at Tubingen, a post to which he was appointed in 1749. The third son, Philipp Friedrich (1721-1768), was extraordinary professor of medicine at Tubingen in 1750, and in 1755 became ordinary professor of botany and chemistry. In the second generation Samuel Gottlieb (1743-1774), the son of Johann Conrad, was appointed professor of natural history at St Petersburg in 1766, and in the following year started on a journey through south Russia and the regions round the Caspian Sea. On his way back he was captured by Usmey Khan, of the Kaitak tribe, and died from the ill-treatment he suffered, on the 27th of July 1774. One of his nephews, Ferdinand Gottlob von Gmelin (1782-1848), became professor of medicine and natural history at Tubingen in 1805, and another, Christian Gottlob (1792-1860), who in 1828 was one of the first to devise a process for the artificial manufacture of ultramarine, was professor of chemistry and pharmacy in the same university. In the youngest branch of the family, Philipp Friedrich had a son, Johann Friedrich (1748-1804), who was appointed professor of medicine in Tubingen in 1772, and in 1775 accepted the chair of medicine and chemistry at Gottingen. In 1788 he published the 13th edition of Linnaeus' _Systema Naturae_ with many additions and alterations. His son Leopold (1788-1853), was the best-known member of the family. He studied medicine and chemistry at Gottingen, Tubingen and Vienna, and in 1813 began to lecture on chemistry at Heidelberg, where in 1814 he was appointed extraordinary, and in 1817 ordinary, professor of chemistry and medicine. He was the discoverer of potassium ferricyanide (1822), and wrote the _Handbuch der Chemie_ (1st ed. 1817-1819, 4th ed. 1843-1855), an important work in its day, which was translated into English for the Cavendish Society by H. Watts (1815-1884) in 1848-1859. He resigned his chair in 1852, and died on the 13th of April in the following year at Heidelberg.

GMUND, a town of Germany, in the kingdom of Wurttemberg,[1] in a charming and fruitful valley on the Rems, here spanned by a beautiful bridge, 31 m. E.N.E. of Stuttgart on the railway to Nordlingen. Pop. (1905) 18,699. It is surrounded by old walls, flanked with towers, and has a considerable number of ancient buildings, among which are the fine church of the Holy Cross; St John's church, which dates from the time of the Hohenstaufen; and, situated on a height near the town, partly hewn out of the rock, the pilgrimage church of the Saviour. Among the modern buildings are the gymnasium, the drawing and trade schools, the Roman Catholic seminary, the town hall and the industrial art museum. Clocks and watches are manufactured here and also other articles of silver, while the town has a considerable trade in corn, hops and fruit. The scenery in the neighbourhood is very beautiful, near the town being the district called Little Switzerland.

Gmund was surrounded by walls in the beginning of the 12th century by Duke Frederick of Swabia. It received town rights from Frederick Barbarossa, and after the extinction of the Hohenstaufen became a free imperial town. It retained its independence till 1803, when it came into the possession of Wurttemberg. Gmund is the birth-place of the painter Hans Baldung (1475-1545) and of the architect Heinrich Arler or Parler (fl. 1350). In the middle ages the population was about 10,000.

See Kaiser, _Gmund und seine Umgebung_ (1888).

FOOTNOTE:

[1] There are two places of this name in Austria. (1) Gmund, a town
in Lower Austria, containing a palace belonging to the imperial
family, (2) a town in Carinthia, with a beautiful Gothic church and
some interesting ruins.

GMUNDEN, a town and summer resort of Austria, in Upper Austria, 40 m. S.S.W. of Linz by rail. Pop. (1900) 7126. It is situated at the efflux of the Traun river from the lake of the same name and is surrounded by high mountains, as the Traunstein (5446 ft.), the Erlakogel (5150 ft.), the Wilde Kogel (6860 ft.) and the Hollen Gebirge. It is much frequented as a health and summer resort, and has a variety of lake, brine, vegetable and pine-cone baths, a hydropathic establishment, inhalation chambers, whey cure, &c. There are a great number of excursions and points of interest round Gmunden, specially worth mentioning being the Traun Fall, 10 m. N. of Gmunden. It is also an important centre of the salt industry in Salzkammergut. Gmunden was a town encircled with walls already in 1186. On the 14th of November 1626, Pappenheim completely defeated here the army of the rebellious peasants.

See F. Krackowizer, _Geschichte der Stadt Gmunden in Oberosterreich_
(Gmunden, 1898-1901, 3 vols.).

GNAT (O. Eng. _gnaet_), the common English name for the smaller dipterous flies (see DIPTERA) of the family _Culicidae_, which are now included among "mosquitoes" (see MOSQUITO). The distinctive term has no zoological significance, but in England the "mosquito" has commonly been distinguished from the "gnat" as a variety of larger size and more poisonous bite.

GNATHOPODA, a term in zoological classification, suggested as an alternative name for the group Arthropoda (q.v.). The word, which means "jaw-footed," refers to the fact that in the members of the group, some of the lateral appendages or "feet" in the region of the mouth act as jaws.

GNATIA (also EGNATIA or IGNATIA, mod. _Anazzo_, near Fasano), an ancient city of the Peucetii, and their frontier town towards the Sallentini (i.e. of Apulia towards Calabria), in Roman times of importance for its trade, lying as it did on the sea, at the point where the Via Traiana joined the coast road,[1] 38 m. S.E. of Barium. The ancient city walls have been almost entirely destroyed in recent times to provide building material,[2] and the place is famous for the discoveries made in its tombs. A considerable collection of antiquities from Gnatia is preserved at Fasano, though the best are in the museum at Bari. Gnatia was the scene of the prodigy at which Horace mocks (_Sat._ i. 5. 97). Near Fasano are two small subterranean chapels with paintings of the 11th century A.D. (E. Bertaux, _L'Art dans l'Italie meridionale_, Paris, 1904, 135). (T. As.)

FOOTNOTES:

[1] There is no authority for calling the latter Via Egnatia.

[2] H. Swinburne, _Travels in the Two Sicilies_ (London, 1790), ii.
15, mentions the walls as being 8 yds. thick and 16 courses high.

GNEISENAU, AUGUST WILHELM ANTON, COUNT NEITHARDT VON (1760-1831), Prussian field marshal, was the son of a Saxon officer named Neithardt. Born in 1760 at Schildau, near Torgau, he was brought up in great poverty there, and subsequently at Wurzburg and Erfurt. In 1777 he entered Erfurt university; but two years later joined an Austrian regiment there quartered. In 1782 taking the additional name of Gneisenau from some lost estates of his family in Austria, he entered as an officer the service of the margrave of Baireuth-Anspach. With one of that prince's mercenary regiments in English pay he saw active service and gained valuable experience in the War of American Independence, and returning in 1786, applied for Prussian service. Frederick the Great gave him a commission as first lieutenant in the infantry. Made _Stabskapitan_ in 1790, Gneisenau served in Poland, 1793-1794, and, subsequently to this, ten years of quiet garrison life in Jauer enabled him to undertake a wide range of military studies. In 1796 he married Caroline von Kottwitz. In 1806 he was one of Hohenlohe's staff-officers, fought at Jena, and a little later commanded a provisional infantry brigade which fought under Lestocq in the Lithuanian campaign. Early in 1807 Major von Gneisenau was sent as commandant to Colberg, which, small and ill-protected as it was, succeeded in holding out until the peace of Tilsit. The commandant received the much-prized order "pour le merite," and was promoted lieutenant-colonel.

A wider sphere of work was now opened to him. As chief of engineers, and a member of the reorganizing committee, he played a great part, along with Scharnhorst, in the work of reconstructing the Prussian army. A colonel in 1809, he soon drew upon himself, by his energy, the suspicion of the dominant French, and Stein's fall was soon followed by Gneisenau's retirement. But, after visiting Russia, Sweden and England, he returned to Berlin and resumed his place as a leader of the patriotic party. In open military work and secret machinations his energy and patriotism were equally tested, and with the outbreak of the War of Liberation, Major-General Gneisenau became Blucher's quartermaster-general. Thus began the connexion between these two soldiers which has furnished military history with its best example of the harmonious co-operation between the general and his chief-of-staff. With Blucher, Gneisenau served to the capture of Paris; his military character was the exact complement of Blucher's, and under this happy guidance the young troops of Prussia, often defeated but never discouraged, fought their way into the heart of France. The plan of the march on Paris, which led directly to the fall of Napoleon, was specifically the work of the chief-of-staff. In reward for his distinguished service he was in 1814, along with York, Kleist and Bulow, made count at the same time as Blucher became prince of Wahlstatt; an annuity was also assigned to him.

In 1815, once more chief of Blucher's staff, Gneisenau played a very conspicuous part in the Waterloo campaign (q.v.). Senior generals, such as York and Kleist, had been set aside in order that the chief-of-staff should have the command in case of need, and when on the field of Ligny the old field marshal was disabled, Gneisenau at once assumed the control of the Prussian army. Even in the light of the evidence that many years' research has collected, the precise part taken by Gneisenau in the events which followed is much debated. It is known that Gneisenau had the deepest distrust of the British commander, who, he considered, had left the Prussians in the lurch at Ligny, and that to the hour of victory he had grave doubts as to whether he ought not to fall back on the Rhine. Blucher, however, soon recovered from his injuries, and, with Grolmann, the quartermaster-general, he managed to convince Gneisenau. The relations of the two may be illustrated by Brigadier-General Hardinge's report. Blucher burst into Hardinge's room at Wavre, saying "_Gneisenau has given way_, and we are to march at once to your chief."

On the field of Waterloo, however, Gneisenau was quick to realize the magnitude of the victory, and he carried out the pursuit with a relentless vigour which has few parallels in history. His reward was further promotion and the insignia of the "Black Eagle" which had been taken in Napoleon's coach. In 1816 he was appointed to command the VIIIth Prussian Corps, but soon retired from the service, both because of ill-health and for political reasons. For two years he lived in retirement on his estate, Erdmannsdorf in Silesia, but in 1818 he was made governor of Berlin in succession to Kalkreuth, and member of the _Staatsrath_. In 1825 he became general field marshal. In 1831 he was appointed to the command of the Army of Observation on the Polish frontier, with Clausewitz as his chief-of-staff. At Posen he was struck down by cholera and died on the 24th of August 1831, soon followed by his chief-of staff, who fell a victim to the same disease in November.

As a soldier, Gneisenau was the greatest Prussian general since Frederick; as a man, his noble character and virtuous life secured him the affection and reverence, not only of his superiors and subordinates in the service, but of the whole Prussian nation. A statue by Rauch was erected in Berlin in 1855, and in memory of the siege of 1807 the Colberg grenadiers received his name in 1889. One of his sons led a brigade of the VIIIth Army Corps in the war of 1870.

See G. H. Pertz, _Das Leben des Feldmarschalls Grafen Neithardt von
Gneisenau_, vols. 1-3 (Berlin, 1864-1869); vols. 4 and 5, G. Delbruck
(ib. 1879, 1880), with numerous documents and letters; H. Delbruck,
_Das Leben des G. F. M. Grafen von Gneisenau_ (2 vols., 2nd ed.,
Berlin, 1894), based on Pertz's work, but containing much new
material; Frau von Beguelin, _Denkwurdigkeiten_ (Berlin, 1892);
Hormayr, _Lebensbilder aus den Befreiungskriegen_ (Jena, 1841); Pick,
_Aus dem brieflichen Nachlass Gneisenaus_; also the histories of the
campaigns of 1807 and 1813-15.

GNEISS, a term long used by the miners of the Harz Mountains to designate the country rock in which the mineral veins occur; it is believed to be a word of Slavonic origin meaning "rotted" or "decomposed." It has gradually passed into acceptance as a generic term signifying a large and varied series of metamorphic rocks, which mostly consist of quartz and felspar (orthoclase and plagioclase) with muscovite and biotite, hornblende or augite, iron oxides, zircon and apatite. There is also a long list of accessory minerals which are present in gneisses with more or less frequency, but not invariably, as garnet, sillimanite, cordierite, graphite and graphitoid, epidote, calcite, orthite, tourmaline and andalusite. The gneisses all possess a more or less marked parallel structure or foliation, which is the main feature by which many of them are separated from the granites, a group of rocks having nearly the same mineralogical composition and closely allied to many gneisses.

The felspars of the gneisses are predominantly orthoclase (often perthitic), but microcline is common in the more acid types and oligoclase occurs also very frequently, especially in certain sedimentary gneisses, while more basic varieties of plagioclase are rare. Quartz is very seldom absent and may be blue or milky and opalescent. Muscovite and biotite may both occur in the same rock; in other cases only one of them is present. The commonest and most important types of gneiss are the mica-gneisses. Hornblende is green, rarely brownish; augite pale green or nearly colourless; enstatite appears in some granulite-gneisses. Epidote, often with enclosures of orthite, is by no means rare in gneisses from many different parts of the world. Sillimanite and andalusite are not infrequent ingredients of gneiss, and their presence has been accounted for in more than one way. Cordierite-gneisses are a special group of great interest and possessing many peculiarities; they are partly, if not entirely, foliated contact-altered sedimentary rocks. Kyanite and staurolite may also be mentioned as occasionally occurring.

Many varieties of gneiss have received specific names according to the minerals they consist of and the structural peculiarities they exhibit. Muscovite-gneiss, biotite-gneiss and muscovite-biotite-gneiss, more common perhaps than all the others taken together, are grey or pinkish rocks according to the colour of their prevalent felspar, not unlike granites, but on the whole more often fine-grained (though coarse-grained types occur) and possessing a gneissose or foliated structure. The latter consists in the arrangement of the flakes of mica in such a way that their faces are parallel, and hence the rock has the property of splitting more readily in the direction in which the mica plates are disposed. This fissility, though usually marked, is not so great as in the schists or slates, and the split faces are not so smooth as in these latter rocks. The films of mica may be continuous and are usually not flat, but irregularly curved. In some gneisses the parallel flakes of mica are scattered through the quartz and felspar; in others these minerals form discrete bands, the quartz and felspar being grouped into lenticles separated by thin films of mica. When large felspars, of rounded or elliptical form, are visible in the gneiss, it is said to have augen structure (Ger. _Augen_ = eyes). It should also be remarked that the essential component minerals of the rocks of this family are practically always determinable by naked eye inspection or with the aid of a simple lens. If the rock is too fine grained for this it is generally relegated to the schists. When the bands of folia are very fine and tortuous the structure is called helizitic.

In mica-gneisses sillimanite, kyanite, andalusite and garnet may occur. The significance of these minerals is variously interpreted; they may indicate that the gneiss consists wholly or in part of sedimentary material which has been contact-altered, but they have also been regarded as having been developed by metamorphic action out of biotite or other primary ingredients of the rock.

Hornblende-gneisses are usually darker in colour and less fissile than mica-gneisses; they contain more plagioclase, less orthoclase and microcline, and more sphene and epidote. Many of them are rich in hornblende and thus form transitions to amphibolites. Pyroxene-gneisses are less frequent but occur in many parts of both hemispheres. The "charnockite" series are very closely allied to the pyroxene-gneisses. Hypersthene and scapolite both may occur in these rocks and they are sometimes garnetiferous.

In every country where the lowest and oldest rocks have come to the
surface and been exposed by the long continued action of denudation in
stripping away the overlying formations, gneisses are found in great
abundance and of many different kinds. They are in fact the typical
rocks of the Archean (Lewisian, Laurentian, &c.) series. In the Alps,
Harz, Scotland, Norway and Sweden, Canada, South America, Peninsular
India, Himalayas (to mention only a few localities) they occupy wide
areas and exhibit a rich diversity of types. From this it has been
inferred that they are of great geological age, and in fact this can
be definitely proved in many cases, for the oldest known fossiliferous
formations may be seen to rest unconformably on these gneisses and are
made up of their debris. It was for a long time believed that they
represented the primitive crust of the earth, and while this is no
longer generally taught there are still geologists who hold that these
gneisses are necessarily of pre-Cambrian age. Others, while admitting
the general truth of this hypothesis, consider that there are
localities in which typical gneisses can be shown to penetrate into
rocks which may be as recent as the Tertiary period, or to pass into
these rocks so gradually and in such a way as to make it certain that
the gneisses are merely altered states of comparatively recent
sedimentary or igneous rocks. Much controversy has arisen on these
points; but this is certain, that gneisses are far the most common
among Archean rocks, and where their age is not known the presumption
is strong that they are at least pre-Cambrian.

Many gneisses are undoubtedly sedimentary rocks that have been brought
to their present state by such agents of metamorphism as heat,
movement, crushing and recrystallization. This may be demonstrated
partly by their mode of occurrence: they accompany limestones,
graphitic schists, quartzites and other rocks of sedimentary type;
some of them where least altered may even show remains of bedding or
of original pebbly character (conglomerate gneisses). More conclusive,
however, is the chemical composition of these rocks, which often is
such as no igneous masses possess, but resembles that of many impure
argillaceous sediments. These sedimentary gneisses (or paragneisses,
as they are often called) are often rich in biotite and garnet and may
contain kyanite and sillimanite, or less frequently calcite. Some of
them, however, are rich in felspar and quartz, with muscovite and
biotite; others may even contain hornblende and augite, and all these
may bear so close a resemblance to gneisses of igneous origin that by
no single character, chemical or mineralogical, can their original
nature be definitely established. In these cases, however, a careful
study of the relations of the rock in the field and of the different
types which occur together will generally lead to some positive
conclusion.

Other gneisses are igneous (orthogneisses). These have very much the
same composition as acid igneous rocks such as granite, aplite,
hornblende granite, or intermediate rocks such as syenite and quartz
diorite. Many of these orthogneisses are not equally well foliated
throughout, but are massive or granitoid in places. They are sometimes
subdivided into granite gneiss, diorite gneiss, syenite gneiss and so
on. The sedimentary schists into which these rocks have been intruded
may show contact alteration by the development of such minerals as
cordierite, andalusite and sillimanite. In many of these orthogneisses
the foliation is primitive, being an original character of the rock
which was produced either by fluxion movements in a highly viscous,
semi-solid mass injected at great pressure into the surrounding
strata, or by folding stresses acting immediately after consolidation.
That the foliation in other orthogneisses is subsequent or
superinduced, having been occasioned by pressure and deformation of
the solid mass long after it had consolidated and cooled, admits of no
doubt, but it is very difficult to establish criteria by which these
types may be differentiated. Those gneisses in which the minerals have
been crushed and broken by fluxion or injection movements have been
called protoclastic, while those which have attained their gneissose
state by crushing long after consolidation are distinguished as
cataclastic. There are also many examples of gneisses of mixed or
synthetic origin. They may be metamorphosed sediments (granulites and
schists) into which tongues and thin veins of granitic character have
been intruded, following the more or less parallel foliation planes
already present in the country rock. These veinlets produce that
alternation in mineral composition and banded structure which are
essential in gneisses. This intermixture of igneous and sedimentary
material may take place on the finest scale and in the most intricate
manner. Often there has been resorption of the older rocks, whether
sedimentary or igneous, by those which have invaded them, and movement
has gone on both during injection and at a later period, so that the
whole complex becomes amalgamated and its elements are so completely
confused that the geologist can no longer disentangle them.

When we remember that in the earlier stages of the earth's history, to
which most gneisses belong, and in the relatively deep parts of the
earth's crust, where they usually occur, there has been most igneous
injection and greatest frequency of earth movements, it is not
difficult to understand the geological distribution of gneissose
rocks. All the factors which are required for their production, heat,
movement, plutonic intrusions, contact alteration, interstitial
moisture at high temperatures, are found at great depths and have
acted most frequently and with greatest power on the older rock
masses. But locally, where the conditions were favourable, the same
processes may have gone on in comparatively recent times. Hence,
though most gneisses are Archean, all gneisses are not necessarily so.
(J. S. F.)

GNEIST, HEINRICH RUDOLF HERMANN FRIEDRICH VON (1816-1895), German jurist and politician, was born at Berlin on the 13th of August 1816, the son of a judge attached to the "Kammergericht" (court of appeal) in that city. After receiving his school education at the gymnasium at Eisleben in Prussian Saxony, he entered the university of Berlin in 1833 as a student of jurisprudence, and became a pupil of the famous Roman law teacher von Savigny. Proceeding to the degree of _doctor juris_ in 1838, young Gneist immediately established himself as a _Privatdozent_ in the faculty of law. He had, however, already chosen the judicial branch of the legal profession as a career, and having while yet a student acted as _Auscultator_, was admitted _Assessor_ in 1841. He soon found leisure and opportunity to fulfil a much-cherished wish, and spent the next few years on a lengthened tour in Italy, France and England. He utilized his _Wanderjahre_ for the purposes of comparative study, and on his return in 1844 was appointed extraordinary professor of Roman law in Berlin university, and thus began a professorial connexion which ended only with his death. The first-fruits of his activity as a teacher were seen in his brilliant work, _Die formellen Vertrage des heutigen romischen Obligationen-Rechtes_ (Berlin, 1845). _Pari passu_ with his academic labours he continued his judicial career, and became in due course successively assistant judge of the superior court and of the supreme tribunal. But to a mind constituted such as his, the want of elasticity in the procedure of the courts was galling. "Brought up," he tells, in the preface to his _Englische Verfassungsgeschichte_, "in the laborious and rigid school of Prussian judges, at a time when the duty of formulating the matter in litigation was entailed upon the judge who personally conducted the pleadings, I became acquainted both with the advantages possessed by the Prussian bureau system as also with its weak points." Feeling the necessity for fundamental reforms in legal procedure, he published, in 1849, his _Trial by Jury_, in which, after pointing out that the origin of that institution was common to both Germany and England, and showing in a masterly way the benefits which had accrued to the latter country through its more extended application, he pleaded for its freer admission in the tribunals of his own country.

The period of "storm and stress" in 1848 afforded Gneist an opportunity for which he had yearned, and he threw himself with ardour into the constitutional struggles of Prussia. Although his candidature for election to the National Assembly of that year was unsuccessful, he felt that "the die was cast," and deciding for a political career, retired in 1850 from his judicial position. Entering the ranks of the National Liberal party, he began both in writing and speeches actively to champion their cause, now busying himself pre-eminently with the study of constitutional law and history. In 1853 appeared his _Adel und Ritterschaft in England_, and in 1857 the _Geschichte und heutige Gestalt der Amter in England_, a pamphlet primarily written to combat the Prussian abuses of administration, but for which the author also claimed that it had not been without its effect in modifying certain views that had until then ruled in England itself. In 1858 Gneist was appointed ordinary professor of Roman law, and in the same year commenced his parliamentary career by his election for Stettin to the Abgeordnetenhaus (House of Deputies) of the Prussian Landtag, in which assembly he sat thenceforward uninterruptedly until 1893. Joining the Left, he at once became one of its leading spokesmen. His chief oratorical triumphs are associated with the early period of his membership of the House; two noteworthy occasions being his violent attack (September 1862) upon the government budget in connexion with the reorganization of the Prussian army, and his defence (1864) of the Polish chiefs of the (then) grand-duchy of Posen, who were accused of high treason. In 1857-1863 was published _Das heutige englische Verfassungsund Verwaltungsrecht_, a work which, contrasting English and German constitutional law and administration, aimed at exercising political pressure upon the government of the day. In 1868 Gneist became a member of the North German parliament, and acted as a member of the commission for organizing the federal army, and also of that for the settlement of ecclesiastical controversial questions. On the establishment of German unity his mandate was renewed for the Reichstag, and in this he sat, an active and prominent member of the National Liberal party, until 1884. In the Kulturkampf he sided with the government against the attacks of the Clericals, whom he bitterly denounced, and whose implacable enemy he ever showed himself. In 1879, together with his colleague, von Hanel, he violently attacked the motion for the prosecution of certain Socialist members, which as a result of the vigour of his opposition was almost unanimously rejected. He was parliamentary reporter for the committees on all great financial and administrative questions, and his profound acquaintance with constitutional law caused his advice to be frequently sought, not only in his own but also in other countries. In Prussia he largely influenced legislation, the reform of the judicial and penal systems and the new constitution of the Evangelical Church being largely his work. He was also consulted by the Japanese government when a constitution was being introduced into that country. In 1875 he was appointed a member of the supreme administrative court (_Oberverwaltungsgericht_) of Prussia, but only held office for two years. In 1882 was published his _Englische Verfassungsgeschichte_ (trans. _History of the English Constitution_, London, 1886), which may perhaps be described as his _magnum opus_. It placed the author at once on the level of such writers on English constitutional history as Hallam and Stubbs, and supplied English literature with a text-book almost unrivalled in point of historical research. In 1888 one of the first acts of the ill-fated emperor Frederick III., who had always, as crown prince, shown great admiration for him, was to ennoble Gneist, and attach him as instructor in constitutional law to his son, the emperor William II., a charge of which he worthily acquitted himself. The last years of his life were full of energy, and, in the possession of all his faculties, he continued his wonted academic labours until a short time before his death, which occurred at Berlin on the 22nd of July 1895.

As a politician, Gneist's career cannot perhaps be said to have been entirely successful. In a country where parliamentary institutions are the living exponents of the popular will he might have risen to a foremost position in the state; as it was, the party to which he allied himself could never hope to become more than what it remained, a parliamentary faction, and the influence it for a time wielded in the counsels of the state waned as soon as the Social-Democratic party grew to be a force to be reckoned with. It is as a writer and a teacher that Gneist is best known to fame. He was a jurist of a special type. To him law was not mere theory, but living force; and this conception of its power animates all his schemes of practical reform. As a teacher he exercised a magnetic influence, not only by reason of the clearness and cogency of his exposition, but also because of the success with which he developed the talents and guided the aspirations of his pupils. He was a man of noble bearing, religious, and imbued with a stern sense of duty. He was proud of being a "Preussischer Junker" (a member of the Prussian squirearchy), and throughout his writings, despite their liberal tendencies, may be perceived the loyalty and affection with which he clung to monarchical institutions. A great admirer and a true friend of England, to which country he was attached by many personal ties, he surpassed all other Germans in his efforts to make her free institutions, in which he found his ideal, the common heritage of the two great nations of the Teutonic race.

Gneist was a prolific writer, especially on the subject he had made
peculiarly his own, that of constitutional law and history, and among
his works, other than those above named, may be mentioned the
following: _Budget und Gesetz nach dem constitutionellen Staatsrecht
Englands_ (Berlin, 1867); _Freie Advocatur_ (ib., 1867); _Der
Rechtsstaat_ (ib., 1872, and 2nd edition, 1879); _Zur
Verwaltungsreform in Preussen_ (Leipzig, 1880); _Das englische
Parlament_ (Berlin, 1886); in English translation, _The English
Parliament_ (London, 1886; 3rd edition, 1889); _Die Militar-Vorlage
von 1892 und der preussische Verfassungsconflikt von 1862 bis 1866_
(Berlin, 1893); _Die nationale Rechtsidee von den Standen und das
preussische Dreiklassenwahlsystem_ (ib., 1895); _Die
verfassungsmassige Stellung des preussischen Gesamtministeriums_ (ib.,
1895). See O. Gierke, _Rudolph von Gneist, Gedachtnisrede_ (Berlin,
1895), an In Memoriam address delivered in Berlin. (P. A. A.)

GNESEN (Polish, _Gniezno_), a town of Germany, in the Prussian province of Posen, in an undulating and fertile country, on the Wrzesnia, 30 m. E.N.E. of Posen by the railway to Thorn. Pop. (1905) 23,727. Besides the cathedral, a handsome Gothic edifice with twin towers, which contains the remains of St Adalbert, there are eight Roman Catholic churches, a Protestant church, a synagogue, a clerical seminary and a convent of the Franciscan nuns. Among the industries are cloth and linen weaving, brewing and distilling. A great horse and cattle market is held here annually. Gnesen is one of the oldest towns in the former kingdom of Poland. Its name, _Gniezno_, signifies "nest," and points to early Polish traditions. The cathedral is believed to have been founded towards the close of the 9th century, and, having received the bones of St Adalbert, it was visited in 1000 by the emperor Otto III., who made it the seat of an archbishop. Here, until 1320, the kings of Poland were crowned; and the archbishop, since 1416 primate of Poland, acted as protector pending the appointment of a new king. In 1821 the see of Posen was founded and the archbishop removed his residence thither, though its cathedral chapter still remains at Gnesen. After a long period of decay the town revived after 1815, when it came under the rule of Prussia.

See S. Karwowski, _Gniezno_ (Posen, 1892).

GNOME, AND GNOMIC POETRY. Sententious maxims, put into verse for the better aid of the memory, were known by the Greeks as gnomes, [Greek: gnomai], from [Greek: gnome], an opinion. A gnome is defined by the Elizabethan critic Henry Peacham (1576?-1643?) as "a saying pertaining to the manners and common practices of men, which declareth, with an apt brevity, what in this our life ought to be done, or not done." The Gnomic Poets of Greece, who flourished in the 6th century B.C., were those who arranged series of sententious maxims in verse. These were collected in the 4th century, by Lobon of Argos, an orator, but his collection has disappeared. The chief gnomic poets were Theognis, Solon, Phocylides, Simonides of Amorgos, Demodocus, Xenophanes and Euenus. With the exception of Theognis, whose gnomes were fortunately preserved by some schoolmaster about 300 B.C., only fragments of the Gnomic Poets have come down to us. The moral poem attributed to Phocylides, long supposed to be a masterpiece of the school, is now known to have been written by a Jew in Alexandria. Of the gnomic movement typified by the moral works of the poets named above, Prof. Gilbert Murray has remarked that it receives its special expression in the conception of the Seven Wise Men, to whom such proverbs as "Know thyself" and "Nothing too much" were popularly attributed, and whose names differed in different lists. These gnomes or maxims were extended and put into literary shape by the poets. Fragments of Solon, Euenus and Mimnermus have been preserved, in a very confused state, from having been written, for purposes of comparison, on the margins of the MSS. of Theognis, whence they have often slipped into the text of that poet. Theognis enshrines his moral precepts in his elegies, and this was probably the custom of the rest; it is improbable that there ever existed a species of poetry made up entirely of successive gnomes. But the title "gnomic" came to be given to all poetry which dealt in a sententious way with questions of ethics. It was, unquestionably, the source from which moral philosophy was directly developed, and theorists upon life and infinity, such as Pythagoras and Xenophanes, seem to have begun their career as gnomic poets. By the very nature of things, gnomes, in their literary sense, belong exclusively to the dawn of literature; their naivete and their simplicity in moralizing betray it. But it has been observed that many of the ethical reflections of the great dramatists, and in particular of Sophocles and Euripides, are gnomic distiches expanded. It would be an error to suppose that the ancient Greek gnomes are all of a solemn character; some are voluptuous and some chivalrous; those of Demodocus of Leros had the reputation of being droll. In modern times, the gnomic spirit has occasionally been displayed by poets of a homely philosophy, such as Francis Quarles (1592-1644) in England and Gui de Pibrac (1529-1584) in France. The once-celebrated _Quatrains_ of the latter, published in 1574, enjoyed an immense success throughout Europe; they were composed in deliberate imitation of the Greek gnomic writers of the 6th century B.C. These modern effusions are rarely literature and perhaps never poetry. With the gnomic writings of Pibrac it was long customary to bind up those of Antoine Favre (or Faber) (1557-1624) and of Pierre Mathieu (1563-1621). Gnomes are frequently to be found in the ancient literatures of Arabia, Persia and India, and in the Icelandic staves. The _priamel_, a brief, sententious kind of poem, which was in favour in Germany from the 12th to the 16th century, belonged to the true gnomic class, and was cultivated with particular success by Hans Rosenblut, the lyrical goldsmith of Nuremberg, in the 15th century. (E. G.)

GNOMES (Fr. _gnomes_, Ger. _Gnomen_), in folk-lore, the name now commonly given to the earth and mountain spirits who are supposed to watch over veins of precious metals and other hidden treasures. They are usually pictured as bearded dwarfs clad in brown close-fitting garments with hoods. The word "gnome" as applied to these is of comparatively modern and somewhat uncertain origin. By some it is said to have been coined by Paracelsus (so Hatzfeld and Darmesteter, _Dictionnaire_), who uses _Gnomi_ as a synonym of _Pygmaei_, from the Greek [Greek: gnome], intelligence. The _New English Dictionary_, however, suggests a derivation from _genomus_, i.e. a Greek type [Greek: genomos], "earth-dweller," on the analogy of [Greek: thalassonomos], "dwelling in the sea," adding, however, that though there is no evidence that the term was not used before Paracelsus, it is possibly "a mere arbitrary invention, like so many others found in Paracelsus" (_N.E.D._ s.v.).

GNOMON, the Greek word for the style of a sundial, or any object, commonly a vertical column, the shadow of which was observed in former times in order to learn the altitude of the sun, especially when on the meridian. The art of constructing a sundial is sometimes termed _gnomonics_. In geometry, a gnomon is a plane figure formed by removing a parallelogram from a corner of a larger parallelogram; in the figure ABCDEFA is a gnomon. Gnomonic projection is a projection of a sphere in which the centre of sight is the centre of the sphere.

A B
-------------------
/ /
/ /
F /------- E /
/ / /
/ / /
-------------------
D C

GNOSTICISM (Gr. [Greek: gnosis], knowledge), the name generally applied to that spiritual movement existing side by side with genuine Christianity, as it gradually crystallized into the old Catholic Church, which may roughly be defined as a distinct religious syncretism bearing the strong impress of Christian influences.

I. The term "Gnosis" first appears in a technical sense in 1 Tim. vi. 20 ([Greek: he pseudonymos gnosis]). It seems to have at first been applied exclusively, or at any rate principally, to a particular tendency within the movement as a whole, i.e. to those sections of (the Syrian) Gnostics otherwise generally known as Ophites or Naasseni (see Hippolytus, _Philosophumena_, v. 2: [Greek: Naassenoi ... hoi heautous Gnostikous apokalountes]; Irenaeus i. 11. 1; Epiphanius, _Haeres._ xxvi. Cf. also the self-assumed name of the Carpocratiani, Iren. i. 25. 6). But in Irenaeus the term has already come to designate the whole movement. This first came into prominence in the opening decades of the 2nd century A.D., but is certainly older; it reached its height in the second third of the same century, and began to wane about the 3rd century, and from the second half of the 3rd century onwards was replaced by the closely-related and more powerful Manichaean movement. Offshoots of it, however, continued on into the 4th and 5th centuries. Epiphanius still had the opportunity of making personal acquaintance with Gnostic sects.

II. Of the actual writings of the Gnostics, which were extraordinarily numerous,[1] very little has survived; they were sacrificed to the destructive zeal of their ecclesiastical opponents. Numerous fragments and extracts from Gnostic writings are to be found in the works of the Fathers who attacked Gnosticism. Most valuable of all are the long extracts in the 5th and 6th books of the _Philosophumena_ of Hippolytus. The most accessible and best critical edition of the fragments which have been preserved word for word is to be found in Hilgenfeld's _Ketzergeschichte des Urchristentums_. One of the most important of these fragments is the letter of Ptolemaeus to Flora, preserved in Epiphanius, _Haeres_. xxxiii. 3-7 (see on this point Harnack in the _Sitzungsberichte der Berliner Akademie_, 1902, pp. 507-545). Gnostic fragments are certainly also preserved for us in the _Acts of Thomas_. Here we should especially mention the beautiful and much-discussed _Song of the Pearl_, or _Song of the Soul_, which is generally, though without absolute clear proof, attributed to the Gnostic Bardesanes (till lately it was known only in the Syrian text; edited and translated by Bevan, _Texts and Studies_,[2] v. 3, 1897; Hofmann, _Zeitschrift fur neutestamentliche Wissenschaft_, iv.; for the newly-found Greek text see _Acta apostolorum_, ed. Bonnet, ii. 2, c. 108, p. 219). Generally also much Gnostic matter is contained in the apocryphal histories of the Apostles. To the school of Bardesanes belongs the "Book of the Laws of the Lands," which does not, however, contribute much to our knowledge of Gnosticism. Finally, we should mention in this connexion the text on which are based the pseudo-Clementine _Homilies_ and _Recognitiones_ (beginning of the 3rd century). It is, of course, already permeated with the Catholic spirit, but has drawn so largely upon sources of a Judaeo-Christian Gnostic character that it comes to a great extent within the category of sources for Gnosticism. Complete original Gnostic works have unfortunately survived to us only from the period of the decadence of Gnosticism. Of these we should mention the comprehensive work called the _Pistis-Sophia_, probably belonging to the second half of the 3rd century.[3] Further, the Coptic-Gnostic texts of the _Codex Brucianus_; both the books of Ieu, and an anonymous third work (edited and translated by C. Schmidt, _Texte und Untersuchungen_, vol. viii., 1892; and a new translation by the same in _Koptische-gnostische Schriften_, i.) which, contrary to the opinion of their editor and translator, the present writer believes to represent, in their existing form, a still later period and a still more advanced stage in the decadence of Gnosticism. For other and older Coptic-Gnostic texts, in one of which is contained the source of Irenaeus's treatises on the Barbelognostics, but which have unfortunately not yet been made completely accessible, see C. Schmidt in _Sitzungsberichte der Berl. Akad._ (1896), p. 839 seq., and "Philotesia," dedicated to Paul Kleinert (1907); p. 315 seq.

On the whole, then, for an exposition of Gnosticism we are thrown back upon the polemical writings of the Fathers in their controversy with heresy. The most ancient of these is Justin, who according to his _Apol._ i. 26 wrote a _Syntagma_ against all heresies (c. A.D. 150), and also, probably, a special polemic against Marcion (fragment in Irenaeus iv. 6. 2). Both these writings are lost. He was followed by Irenaeus, who, especially in the first book of his treatise _Adversus haereses_ ([Greek: elegchou kai anatropes tes pseudonymou gnoseos biblia pente], c. A.D. 180), gives a detailed account of the Gnostic heresies. He founds his work upon that of his master Justin, but adds from his own knowledge among many other things, notably the detailed account of Valentinianism at the beginning of the book. On Irenaeus, and probably also on Justin, Hippolytus drew for his _Syntagma_ (beginning of the 3rd century), a work which is also lost, but can, with great certainty, be reconstructed from three recensions of it: in the _Panarion_ of Epiphanius (after 374), in Philaster of Brescia, _Adversus haereses_, and the Pseudo-Tertullian, _Liber adversus omnes haereses_. A second work of Hippolytus [Greek: Kata pason haipeseov elegchos] is preserved in the so-called _Philosophumena_ which survives under the name of Origen. Here Hippolytus gave a second exposition supplemented by fresh Gnostic original sources with which he had become acquainted in the meanwhile. These sources quoted in Hippolytus have lately met with very unfavourable criticisms. The opinion has been advanced that Hippolytus has here fallen a victim to the mystification of a forger. The truth of the matter must be that Hippolytus probably made use of a collection of Gnostic texts, put together by a Gnostic, in which were already represented various secondary developments of the genuine Gnostic schools. It is also possible that the compiler has himself attempted here and there to harmonize to a certain extent the various Gnostic doctrines, yet in no case is this collection of sources given by Hippolytus to be passed over; it should rather be considered as important evidence for the beginnings of the decay of Gnosticism. Very noteworthy references to Gnosticism are also to be found scattered up and down the _Stromateis_ of Clement of Alexandria. Especially important are the _Excerpta ex Theodoto_, the author of which is certainly Clement, which are verbally extracted from Gnostic writings, and have almost the value of original sources. The writings of Origen also contain a wealth of material. In the first place should be mentioned the treatise _Contra Celsum_, in which the expositions of Gnosticism by both Origen and Celsus are of interest (see especially v. 61 seq. and vi. 25 seq.). Of Tertullian's works should be mentioned: _De praescriptione haereticorum_, especially _Adversus Marcionem_, _Adversus Hermogenem_, and finally _Adversus Valentinianos_ (entirely founded on Irenaeus). Here must also be mentioned the dialogue of Adamantius with the Gnostics, _De recta in deum fide_ (beginning of 4th century). Among the followers of Hippolytus, Epiphanius in his _Panarion_ gives much independent and valuable information from his own knowledge of contemporary Gnosticism. But Theodoret of Cyrus (d. 455) is already entirely dependent on previous works and has nothing new to add. With the 4th century both Gnosticism and the polemical literature directed against it die out.[4]

III. If we wish to grasp the peculiar character of the great Gnostic movement, we must take care not to be led astray by the catchword "Gnosis." It is a mistake to regard the Gnostics as pre-eminently the representatives of intellect among Christians, and Gnosticism as an intellectual tendency chiefly concerned with philosophical speculation, the reconciliation of religion with philosophy and theology. It is true that when Gnosticism was at its height it numbered amongst its followers both theologians and men of science, but that is not its main characteristic. Among the majority of the followers of the movement "Gnosis" was understood not as meaning "knowledge" or "understanding," in our sense of the word, but "revelation." These little Gnostic sects and groups all lived in the conviction that they possessed a secret and mysterious knowledge, in no way accessible to those outside, which was not to be proved or propagated, but believed in by the initiated, and anxiously guarded as a secret. This knowledge of theirs was not based on reflection, on scientific inquiry and proof, but on revelation. It was derived directly from the times of primitive Christianity; from the Saviour himself and his disciples and friends, with whom they claimed to be connected by a secret tradition, or else from later prophets, of whom many sects boasted. It was laid down in wonderful mystic writings, which were in the possession of the various circles (Liechtenhahn, _Die Offenbarung im Gnosticismus_, 1901).