37 



GEOROIUM SIDUS. 



GILDING. 



Mrt, .nytmn in Bithynia, where he had an estate. (' Geoponika,' book 

 v.. oh. 6 and 36.) The work U curium, u giving * court* of ancient 

 agriculture collected from the best authorities then existing. The beet 

 edition of the ' Oeoponika ' U that of N. Niclas, in Greek ami Latin, 

 with not** and indexe*, 4 vols. Svo, Leipzig, 1781. 



OEUKGIUM SIDUS. [UnAJici.] 



MAN -II. n I! As it* name implie*, thU alloy was originally 

 produced in Germany, and wai obtained by smelting an ore found at 

 Hilburghwuen, near Buhl, in Henneberg. An alloy, however, very 

 similar in appearance and propertiei has long been known to the 

 Chinese under the name of pakfoxg, or white metal 



German ailrer U compoced of the metal* nickel, copper, and zinc, 

 though in lomewhat variable proportion*. The following are examples 

 of the amount* of the several metal* contained in four specimens, 

 each of different quality : 



i r 

 .Nickel 

 Zinc 



I. 



59-1 

 U-8 

 2G-0 



100-0 



II. 

 60 

 20 

 20 



100 



III. 

 Si'O 

 20-8 

 24-4 



100-0 



IV. 

 45-7 

 S4-S 

 20-0 



100-0 



No. 1 is perhaps the commonest made. No. 2 is much used. No. S 

 U a very beautiful alloy, but little inferior in beauty to silver itself ; 

 it U sometimes called tUcirum. No. 4 is the richest in nickel that 

 can be conveniently worked. For articles requiring much soldering, 

 about 3 per cent, of lead is introduced ; and where brittleness is not 

 an objection, 2| per cent, of iron may be added; the hardness and 

 susceptibility of high polish being in the latter case greatly heightened. 

 TutcHuij, a kind of German silver used in casting operation*, is com- 

 posed of 457 of copper, 17'4 of nickel, and 36*9 of zinc. 



In furnace operations wjth German silver a quantity of zinc is 

 always volatilised and oxidised, and must be allowed for by at first 

 adding a larger quantity of that metal than is required to form the 

 alloy. 



GESTURE. [ORATORY.] 



UKT.K, the name of a northern tribe mentioned in Roman history, 

 inhabiting the country on both bank* of the Danube, near its estuary, 

 and along the western shores of the Euxine. [DACIA, in GEOO. Div.] 



(JUKE, a species of butter used by the natives of India, and pre- 

 pared by boiling, so that it will keep for a considerable time ; it is 

 sometimes used when a year old. The milk, when first taken from the 

 animal, is boiled in earthen pots for at least an hour, and frequently 

 for two and even three hours ; it is then allowed to cool, and a little 

 curdled milk, called Dhye, is added to promote its coagulation. By 

 the next morning the whole mass has been converted into dhye, or 

 coagulated acid milk. About five or six inches in depth are then token 

 from the top of each pot and put into an earthen jar, where it is 

 churned by turning round in it a split bamboo with a very quick 

 motion. After half an hoar's churning, some hot water is added, and 

 the operation is continued for another half-hour, when the butter 

 forms. When this butter has been kept two or three days, and has 

 become rancid, as it will during that time in so hot a climate, it is 

 melted in an earthen pot, and boiled until all the water that may be 

 mixed with it is evaporated ; a little dhye and salt, or betel-leaf, is 

 then added, and it is put into pots to be kept for use. It has a strong 

 smell, and, although very distasteful to European*, is in general con- 

 sumption among all the natives who can attend to buy it. Ghee is a 

 very important article of internal traffic through a great part of India. 



liHU'.ELUNKS. [UiKU'HS.] 



GIBBOUS, convex on both sides ; a term particularly applied to the 

 moon when more than half grown. 



I' (Law), donum, donalio, is the transferring of the property in 

 a thing by one man to another, voluntarily and without any valuable 

 consideration. 



. The giver is called the donor, and he to whom the thing is given is 

 called the donee. By the common law, real estate might pas* as a gift 

 by livery of seisin without deed ; but by stat. 29 Charles II. c. 8, a 

 deed or note in writing is rendered necessary to the transfer of real 

 estate. To complete a gift of good* and chattels, not effected by 

 writing, delivery is absolutely necessary ; for until then the transaction 

 is not properly a gift, but a contract, and the English law will not com- 

 pel a man to perform his contract unless it is founded on good or 

 valuable consideration. 



Gift* are looked at with some degree of suspicion by the law of 

 England, and are in some cases declared void, as against creditors and 

 purchasers for a valuable consideration. [BANKRUPT.] 



The distinction* laid down by the civil law as to gifts were numerous. 

 It distinguished gifts into two rlsimm, proper and improjwr: tli 

 gift being such as is recognised by the English law; tin' improper, gifts 

 in consideration of marriage, and that species of gift termed doiialto 

 mortu catud. According to the law of England, marriage is a valuable 

 consideration, and consequently gifts upon that account ore supported 

 gainst purchasers and creditors. 



Many curious distinctions relating to gifts exist in the Hindoo law. 

 (Sec Cplebrooke's Digest, Hindoo Law,' b. ii., c. 4.) As to the law 

 regulating voluntary gifu established by the Code Napoleon, see ' Cod. 

 CiT./b.8,tit.2. 



GILDING. Although then are many varieties of gilding, the only 

 kinds which need separate mention in this place are Mdal-ytldiitg and 

 Wood-gilding. The reader will find an account of the modern process 

 of EUctronililiag, under ELIXTRO-MKTALLCRUT ; of Filirt-gildiug, under 

 GOLD LACE MANUFACTURE; of China-yMuv/, under PORCELAIN ; and 

 of Soot-gilding, under BOOKBINDING. 



Uftal-gililing. The process of metal-gilding is one of the most 

 delicate in the manufactures in metal ; seeing that its success depends 

 on a nicety of eye, a dexterity of hand, and a practical acquaintance 

 with the chemical operations involved in it, which cannot be acquired 

 without several mouths' or even years' experience. Mechanical error* 

 and difficulties are in most cases detected and remedied with n,. li 

 greater facility than those which arise in the chemical brau 

 manufactures. To these latter the processes of gilding and col 

 are particularly subject, and more especially that of gilding. 



The gold made use of for the purpose of metal-gilding i* called " fine 

 gold," and is perfectly free from alloy. Its form is that which, in 

 metals, is usually termed " shot," from its having been poured or shot 

 when in a fluid state, into cold water. This operation divides 

 pieces of various shapes and sizes, from the smallest grain, scarcely 

 perceptible by the naked eye, to the dimensions of a pea or a nut 

 This form of the metal is best adapted for the gilder's purpose. 



The union of the gold with the m. til to be gilt is effected through 

 the agency of mercury. The gold and mercury are first combined, by 

 boiling the former in about five or six times its weight of the latter. 

 These proportions are put into an iron ladle, which must have been 

 previously lined with a coating of whiting and water, and then care- 

 fully and thoroughly dried. Should there be any moisture left in the 

 lining, or if any cracks should expose the naked surface of the iron, 

 the ebullition of the mercury is so. rapid there, owing to tin 

 rapid conduction of the heat, that a portion of the amalgam would be 

 thrown out l>y the violence of the action. It is most economical to 

 place the ladle and its contents within the heated iron cylinder used for 

 the evaporation of the mercury from the articles when gilt, l.y which 

 arrangement a considerable portion of the mercury which U evaporated 

 during the process is retained by the condensers. The time necessary 

 for dissolving all the gold in the mercury varies according to the hard- 

 ness or softness of the gold (that which has been more anxiW by the 

 refiner appearing browner than the harder and yellower, and requiring 

 a longer time for complete solution), ajid according to the larger or 

 smaller size of the fragments of gold mode use of. In general, half a 

 troy pound of gold is completely dissolved by being kept at the boiling 

 temperature of mercury for about twenty or twenty-five minutes. It 

 is obvious that the boiling should be as gentle as possible, since fart 

 boiling ensures no higher a temperature, and evaporates a greater 

 quantity of quicksilver. 



When it has been sufficiently boiled, the amalgam is poured out into 

 cold water, by which it loses a great part of its fluidity, and becomes 

 semi-fluid; the consistence depending, of course, on the quantity of 

 quicksilver originally made use of, aud the proportion of it that has 

 been evaporated. The amalgam is then put into a piece of chamois 

 skin, and squeezed ; by which mean* the particles of quicksilver escape 

 through the pores of the leather, while those of the gold are safely 

 retained. When the mass is felt to be hard and unyielding w itliin tin- 

 leather, it is weighed, and its value is determined by considering five 

 parts by weight of the amalgam as equal to one part l.y weight of the 

 gold employed. The amalgam then, if good, is of about the consistence 

 of a stiff clay, has a greasy and gritty feel on being divided l.y a bone 

 spatula, and is in the most convenient state for being weighed out into 

 the portions requisite for each respective quantity of work. If how- 

 ever the gold be adulterated or the mercury be impure, the amalgam 

 often approaches more or less to fluidity, appears dirty, and deposits a 

 block adhesive scum on every thing with which it comes in contact. 

 The maui object of bringing the amalgam to this consistence and these 

 proportions is to have it in a form convenient for division and appor- 

 tionment, as well as for the sake of having a uniform standard by In. h 

 to ascertain the quantity aud value of the gold employed. As, h..\v- 

 ever, this consistence is not adapted for being applied to its intended 

 purpose, without a greater or less dilution by being again boiled for a 

 short time in mercury, many metal-gilders, especially those wli.' pro\id 

 their own gold, prefer to weigh out the gol<l which they intend to use, 

 ami then to mix it at once with the quantity of quicksilver which 

 experience ho* taught them to be proper and necessary, and win. h 

 varies according to the nature of the articles to be covered with it : 

 for such articles as are wrought into deeply indented or highly 

 mcnted patterns, or which are to have their surfaces completely 

 covered, require a more fluid amalgam than those which have a 

 smoother superficies, or which are to be only partially gilt. 



On tile application of this amalgam to the surface* of copper, 

 brazen, or mixed metal articles, it is found that, a- 



1 affinity, and consequently no principle of mutual cohesion, 

 between the substances thus brought into contact, the direct tin 

 them is impossible. Nor can it be effected by allowing them to remain- 

 in contact for any length of time. The intrivi-ntion of u solution of 

 nitrate of mercury is therefore used. This salt i- made l.y pmiring a 

 table-spoonful of quicksilver into about a quart of strong nitric acid, 

 which is termed in commerce " gilders' aquafortis ; " the red fume* of 

 nitrous gas are instantly evolved, and the mercury is rapidly united 



