GUERITE. 



GUM. 



550 



Ghibelline. The Ghibellinea adopted as a symbol a white rose or a red 

 lily ; the Guelphs chose the eagle, already the arms of the Guelph 

 family. But in the long struggle that ensued many alternate changes 

 took place in each city, where sometimes the Guelphs, and sometimes 

 the Ghibellines, gained the upper hand. [FLORENCE ; GENOA, HISTORY 

 OF, in GEOQ. Drv.] Most of the powerful nobles in Northern Italy, 

 the Visconti, Doria, Delia Scab, Pelaviciuo, were Ghibellines; the 

 Anjou dynasty, which the popes had called to the throne of Naples, 

 were the main support of the Guelphs. As the emperors, engrossed by 

 their German affairs, neglected and dropped their hold upon Italy, the 

 names of Guelph and Ghibelline lost their original meaning, and the 

 struggle became one of personal or municipal ambition among the 

 Italians themselves, the Ghibellines being for the most part animated 

 by a spirit of aristocracy, the Guelphs professing to be favourers of a 

 popular form of government. [DANTE, in Bioo. Drv.] But even this 

 distinction was often belied by facts, and the leaders of the Guelphs 

 in some towns tyrannised over their countrymen ; whilst in some 

 instances, as at Genoa, the Ghibellinea formed really the popular party. 

 In the 15th century the names of Guelphs and Ghibellines had become 

 a mere traditional shadow, and at last the popes themselves united with 

 the emperor in extinguishing the independence of the Italian republics, 

 without distinction of parties. (Sismondi, ' History of the Italian 

 Republics ;' Raumer, ' Geschichte der Hohenstaufen.) 



The House of Guelph, originating in Italy, settled in Germany In the 

 llth century, and very shortly acquired large territorial piissessions. 

 From this family has proceeded both the lines of Brunswick-Oels and 

 Luneburg; it gave emperors to Germany, dukes to Saxony, Carinthiu, 

 and Bavaria ; one branch became also Dukes of Este in Italy, and the 

 House of Hanover claims descent from both branches. [BRUNSWICK, 

 HISTORY OF, in GEOQ. Div. ; ESTE, in Bioo. Div.] 



GUERITE is the term applied in fortification to the projecting 

 masonry sentry boxes to be seen in many old fortresses, at the salient 

 angles of works on the top of the revetment. They are provided with 

 loop-holes, so as to enable a few men in them thoroughly to command 

 the foot of the escarp along the whole extent of the face. They have, 

 however, the disadvantage of enabling an enemy the more easily to 

 take up the prolongation of works to place his enfilade batteries, by 

 giving well marked points at the extremities of the faces : they have, 

 therefore, not been much used of late years. 



iM.'ILDS. [MtrsiciPAL CORPORATIONS.] 



GUILLOTINE, an instrument for the infliction of capital punish- 

 ment, proposed to the National Assembly of France by Joseph Ignace 

 (iiiillntin, a physician, a native of Xaintes, and a member of the 

 Assembly ; and which from him took its name. It was adopted by a 

 decree of the 20th of March, 1792, and used for the first time on 

 April 25th. 



This instrument, under other names, had existed as a means of 

 public execution long before, in Germany, Bohemia, Italy, Scotland, 

 England, and even in Persia and India. 



Crusius in his ' Annales Suevici/ fol. 1595-6, torn, ii., p. 296, says, 

 ' Antiquis autem temporibus, in Gennania etiam, decollatio non gladio 

 fiebat, sed querno ligno, habente scindens acutissime ferrum. Addit 

 uannus, se vidisse tale instrumentum Hake in vetere Nosodocheo 

 (Siechaus) priusquam id destrueretur : et hodiernum ibi sodificaretur. 

 Effcrebatur inde ilia machina, si quis plectendus esset : supplicioque 

 peracto, eodem referebatur." " Postea usus gladii successit." 



I n German this instrument was called der Planke der IJeil (the plank 

 of wood), and in older language Paibeil (the falling hatchet). In Bohe- 

 mia it wan c illed llaijff, something akin to the plank. In Italy it was 

 known by the name of Mannaui, and an engraving of it may be seen 

 in ' Achillis Bocchii Bonon. Symbolicarum Questionum,' lib. v., 8vo., 

 Bonon, 1555, p. 36. There is a very beautiful engraving of the 

 ( Vrinan instrument in a representation of the beheading of the son of 

 Titus Manlius, by Henry Aldegrevers, dated 1553. Evelyn, in his 

 lire,' vol. i., p. 170, states that he saw a similar instrument at 



IVimecuik, in his ' Description of Tweeddale," pp. 16, 17, speaking of 

 the Regent Morton of .Scotland, says : " Thin mighty earl, for the 

 pleasure of the place and the salubrity of the air, designed here a noble 

 recess and retirement from worldly business, but was prevented by his 

 unfortunate and inexorable death, three years after, anno 1581, being 

 accused, condemned, and executed by the Maiden at the Cross of 

 Edinburgh, as art and part of the murder of King Henry, earl" of 

 Darnley, father to King James VI., which fatal instrument, at least 

 the pattern thereof, the cruel Regent had brought from abroad to 

 behead the Laird of Pennecuik of that ilk, who notwithstanding died 

 in his bed, and the unfortunate earl was the first himself that hand- 

 seti^d that merciless Maiden, who proved so soon after his own 

 executioner." 



In England, what has been since called the Guillotine was used 



only at Halifax in Yorkshire, and confined even there to the punish- 



inent of feloni.M committed within the forest of Hardwick. Its use at 



< is traced as far back as the time of Edward III. It was in 



that the last malefactors there suffered by it. (Watson's ' Hist. 



..i ll.ilif,tx,' i 



Joseph Ignace Guillotin, who revived the use of this instrument, in 

 France, is supposed, by many, to have perished at a later period of the 

 Revolution, like the Regent Morton, by his own invention. But this is 



not correct. He died a natural death, 26th May, 1814, at the age of 

 76. ('Biogr. Uuiverselle.') 



GUINEA. [MONEY.] 



GUITAR, a musical instrument which, in various shapes, may be 

 traced to the remotest periods of antiquity. The word is derived from 

 the Greek KiSapa, and comes immediately to us through the French 

 Guitare, though it is nearly the same in the Italian, Spanish, and 

 German languages. The terms Cittern and Gittern, used by the old 

 English poets, are but corruptions of the primitive word. 



The English and French guitar of the last century was wide and 

 thin in body, short in the neck, and strung with wire. The modern 

 guitar, which is of the Spanish kind, and differing little from the lute, 

 consists of a body from seventeen to eighteen inches in length, four in 

 depth, and of a neck of about sixteen inches, the latter carrying a 

 finger-board divided by seventeen frets. It has six strings, three being 

 of silk covered with silvered wire, and three of catgut. 



The compass of this elegant instrument is from E below the base 

 staff, to A above the treble staff, including all the intermediate tones 

 and semitones. The best and cheapest guitars are made in Germany, 

 and may be purchased in London at a moderate price. 



GUM is a proximate principle of vegetables, of more universal occur- 

 rence than any other secretion by plants. It is in reality the material 

 generally prepared by them for their own growth and nourishment, 

 and is at first always in a state of solution, in which condition it mostly 

 remains so long as it is contained in the internal tUsues of plants ; but 

 when it escapes to the exterior of the bark it frequently becomes 

 thickened, and even solid and pulverisable. It is probable that it 

 never escapes to the surface unless some wound of the bark has been 

 made, either by disease, the punctures of insects, the agency of fungi, 

 by the knife, or by the more rapid growth of the inner wood, pro- 

 ducing by its distension a rupture of the bark. The escape of the 

 gum termed ceratin from plum and cherry trees may always be 

 regarded as an indication of unhealtliiness ; the immediate cause of 

 escape is the presence of a small corkscrew-like fungus termed 

 Namaipora crocea. 



Gum is known in commerce only in the solid state ; the term is 

 often erroneously applied to substances which are a mixture of gum 

 with resins, and which are properly gam-mint, such as ammoniacum, 

 asafcctida, and the like, and even to substances which contain no portion 

 of gum, such as euphorbium. 



Arranging the gums according to the facility with which they are 

 acted upon by water, we have at one end of the list gum-acacia, or 

 gum-arabic as it is most usually called, and at the other end gum- 

 tragacanth. Gum-arabic forms a perfect solution with even cold water, 

 and to this variety of gum the term arabin is given ; gum-tragacauth 

 on the other hand, though swelling xip immensely when digested in 

 water, and at first sight appearing to form a solution, does not really 

 dissolve, but forms a thick mucilage, and to this modification of gum 

 the term bassorin is applied. The derivation of the name arabin is 

 obvious, that of bassorin is obtained from basora gum, a variety of 

 tragacanth that comes from Bassora, and which contains scarcely a 

 trace of arabin. Other members of the series of true gums are 

 mixtures in variable proportions of these two gum modifications. 



Arabin (CuH^O,,) is colourless, tasteless, and inodorous. Specific 

 gravity, from 1'3 to 1 '5. It is uncrystallisable. Its solution slightly 

 reddens litmus-paper, and rotates to the left a polarised ray. Dilute 

 sulphuric acid converts it first into dextrin and then into grape-sugar ; 

 strong sulphuric acid carbonises it : nitric acid converts it into mucic 

 ami oxalic acids. It forms soluble compounds with the alkalies and 

 alkaline earths. It is precipitated from solution by persalts of iron, 

 proto-salts of mercury, and subsalts of lead. The reaction with per- 

 salt of iron is characteristic of arabin : if the solutions are strong, 

 a brown gelatinous precipitate is formed, soluble with difficulty in 

 boiling water; if the solutions are weak, a yellowish precipitate is 

 produced only after the lapse of some time ; thus one part of gum- 

 arabic in 100 parts of water gives a precipitate with persulphate of 

 iron after the mixture has stood for twenty-four hours. 



Ba&orin is soluble in dilute acids or alkalies, and by very long 

 boiling even in water, but in each case it is probably converted into 

 arabin. Like arabin it is insoluble in alcohol or ether, and is oxidised 

 by nitric acid to mucic and oxalic acids. The presence of bassorin 

 gives the peculiar mucilaginous or viscous consistence to the decoctions 

 of linseed, quince-seed, marsh-mallow root, &c. 



Most of the commercial gums are obtained by incisions made in the 

 bark of several species of acacia growing in Arabia, India, Upper 

 Egypt, Senegal, &c. The specimens differ considerably in colour, even 

 when obtained from the same species. Genuine gum-arabic occurs in 

 pieces from the size of a pea to that of a walnut, or larger, which are 

 irregular in shape, or roundish or angular ; either white, yellowish, or 

 dark wine yellow ; scarcely any odour ; taste mawkish, glutinous. 

 Sp. gr. 1'316 to 1'482. It breaks easily into small irregular pieces; 

 fracture uneven, vitreous ; dissolves almost completely in water ; 100 

 parts of water at '212 of Fahr. take up 19 parts of gum. The solution 

 is almost transparent when made with cold water. Gum, when in 

 powder, is often adulterated with starch, the presence of which is 

 detected by tincture of iodine ; or when cold water is used for the 

 solution of the gum, the starch will remain undissolved. The mucilage 

 made with cold water is not only purer, but keeps better, and for ill 



