109 



LAO'COON. 



LAPIDARY WORK. 



110 





which oxidises in water with the evolution of hydrogen gas, and is 

 converted into a white hydrate. 



Oxide of lanthanium, in the purest state in which it has hitherto 

 been obtained, is nearly white or of a light salmon colour without any 

 admixture of brown, or brownish red ; there is every reason to believe 

 that the colour is owing to some impurity, from which it has not been 

 hitherto possible to free it. It undergoes no alteration by calcinatiqn 

 at a red heat in close vessels ; it restores the blue colour of reddened 

 litmus-paper ; when sprinkled with water, it is gradually converted 

 into a hydrate, and becomes a bulky white powder; this alteration 

 occurs very rapidly in boiling water ; it dissolves very readily in acids, 

 even when dilute ; when boiled in a solution of chloride of ammonium, 

 it expels ammonia and an ammonia-chloride of lanthaniiim is formed. 

 The equivalent of lanthaniiim is 46'4. Hydrate and carbonate of lan- 

 thanium are both insoluble in carbonate of ammonia. 



Oxide of Lanthanium (LaO). Lanthanium seems to combine with 

 oxygen in one proportion only ; thia oxide dissolves in hydrochloric 

 acid without evolving chlorine. 



Chloride of Lanthanium (LaCl). When a solution of oxide of lan- 

 thanium in hydrochloric acid is evaporated over sulphuric acid, pris- 

 matic crystals of chloride of lanthanium of a rose-colour are obtained ; 

 it deliquesces on exposure to the ah*, readily dissolves in alcohol, to the 

 flame of which it imparts no colour. This salt melts in its water of 

 crystallisation, gives off hydrochloric acid, and leaves a mixture of 

 chloride and oxychloride of lanthanium. 



Nttrate of Lanthanium (LaO,N0 5 ) is obtained by dissolving the 

 oxide in nitric acid. It crystallises with difficulty, and forms a rose- 

 coloured saline mass which is deliquescent and soluble in alcohol ; the 

 form of the crystal is a prism, and it contains no water of crys- 

 tallisation. 



Carbonate of Lanthanium (LaO,CO,). The neutral compound is 

 obtained by precipitating the soluble salts of lanthanium with carbonate 

 of soda. It is a white flocculent precipitate, which on drying becomes 

 a white adherent powder. 



It hag been found by Mosander that a mineral, which was supposed 

 to be a protocarbonate of cerium, contained only a trace of this metal, 

 and consisted almost entirely of a compound of 1 equivalent of carbonic 

 acid with 3 equivalents of oxide of lanthanium. 



Sulphate of Lanthanium (LaO,S0 3 + 3Aq). Dilute sulphuric acid 

 very readily dissolves the oxide ; by evaporation, acicukr radiating 

 amethystine-coloured crystals are obtained. Possibly however the red 

 colour is due to didymium. This salt gives off water, but does not 

 melt at a low red heat. 



Double nitrate of Lanthanium and Magnesium ( LaO,NO s + MgO, 

 N0 5 + 8Aq). Dilute nitric acid is saturated with equivalent proportions 

 of oxide of lanthanium and magnesia, and the solution left to spon- 

 taneous evaporation over sulphuric acid. After a time large, shining, 

 white, crystals are deposited : they possess a sweet styptic taste, and 

 are only very slightly deliquescent. 



The salt* of lanthanium give white precipitates with phosphoric and 

 oxalic acids and ferrocyanide of potassium, but neither hydrosulphuric 

 acid nor tincture of galls produces any change. 



LAO'COON, according to ancient fable, was the son of Priam 

 (according to some, of Antenor), and a priest of Apollo, or as some 

 y of Poseidon, during the Trojan war. While offering, in the exer- 

 cise of his office, a bullock to render Poseidon propitious to the Trojans, 

 two enormous serpents issued from the sea, and, having first destroyed 

 his two sons, whom he vainly endeavoured to save, attacked Laocoon 

 himself, and, winding themselves round hia body, crushed him to death 

 in their folds. This dreadful punishment was inflicted by the goddess 

 Athene for the part Laocoon had taken in endeavouring to dissuade 

 the Trojans from admitting into Troy the fatal wooden horse, which 

 the crafty Greeks had consecrated to Athene. 



An enduring celebrity has been gained for this story from its forming 

 the subject of one of the most remarkable groups in sculpture which 

 time has spared to us. It represents the agonised father and his 

 youthful sons, one on each side of him, writhing and expiring in the 

 complicated folds of the serpents. The figures are naked, the drapery 

 that is introduced being only used to support and fill up the compo- 

 sition. This superb work of art, which Pliny describes inaccurately as 

 consisting of only a single block of marble, is formed of five pieces of 

 marble (but in spite of this mistake there seems to be no doubt in the 

 opinion "f the learned that this is the identical group alluded to by 

 . originally decorated the baths of Titus, among the ruins of 

 whi'.hj on the aide of the Eaquiline hill, it was found in the year 1506. 

 The names of the sculptors who executed it are also recorded. Pliny 

 (xxxvi. 5) says, " Laocoon, which is in the house or palace (domo) of 

 th. mperor Titus, is a work to be preferred to all others, either in 

 painting or scxilpture. Those great artists Agesander, and Polydorus, 

 and Athenodorus, Khodiana, executed the principal figure (eum), and 

 the sons, and the wonderful folds of the serpents, out of one block of 

 Warble." 



There has been much difference of opinion among antiquaries on 

 several points connected with this group : first, as to the date of the 

 artists ; Winckclmann contending that they are of a good period of 

 Greek art, and as early as Lysippus : the next 'question discussed has 

 been, whether the sculptor was indebted for the subject to Virgil's fine 

 description (' vEneid,' ii., v. 200), or whether the poet was indebted to 



the artist. With respect to date, the most careful consideration seems 

 to- fix these sculptors as late as the early emperors ; and Lessing, whose 

 work on the Laocoon deserves the attention of all who take an interest 

 in the philosophy and capabilities of art, believes that they lived in the 

 reign of Titus. With regard to the subject, it is most probable that 

 the story, being well known, offered advantages for illustration to the 

 sculptor, as it did for description to the poet. As Virgil's priest was 

 habited in his robes during the exercise of his priestly functions, and 

 the group under consideration is entirely naked, the argument is 

 additionally strengthened against the assumption that the artist 

 borrowed from the poet. It is more natural to believe that both drew 

 from a common source, and treated the subject in the way they con- 

 sidered best adapted to the different arts they exercised ; the sculptor's 

 object being concentration of effect, the poet's amplification and brilliant 

 description. 



This group is justly considered, by all competent judges, to be a 

 masterpiece of art. The subject is of the most affecting and interesting 

 kind ; and the expression in every part of the figures reaches, but does 

 not exceed, the limits of propriety. Intense mental suffering is por- 

 trayed in the countenances, while the physical strength of all the three 

 figures is evidently sinking under the irresistible power of the huge 

 reptiles wreathed around their exhausted limbs. One eon, in whose 

 side a serpent has fixed his deadly fangs, seems to be fainting ; the 

 other, not yet bitten, tries (and the futility of the attempt is faithfully 

 shown) to disengage one foot from the serpent's embrace. The father, 

 Laocoon himself, is mighty in his suffering : every muscle is in extreme 

 action, and his hands and feet are convulsed with painful energy. Yet 

 there is nothing frightful, disgusting, or contrary to beauty in the 

 countenance. Suffering is faithfully and strongly depicted there, but 

 it is rather the exhibition of mental anguish than of the ugly and 

 undignified contortions of mere physical pain. The whole of this 

 figure displays the most intimate knowledge of anatomy and of outward 

 form ; the latter selected with care, and freed from any vulgarity of 

 common individual nature : indeed the single figure of Laocoon may 

 be fairly referred to as one of the finest specimens existing of that 

 combination of truth and beauty which is so essential to the production 

 of perfect sculpture, and which can alone insure for it lasting admira- 

 tion. The youths are of a smaller standard than the proportion of the 

 father ; a liberty hardly justifiable, but taken probably with the view 

 of heightening the effect of the principal figure. The right arm of the 

 figure of Laocoon is a restoration. Some have thought that the 

 original action was not extended, but that this arm was bent back 

 towards the head ; and have supported their hypothesis by the fact of 

 there being a rough and broken surface where they think the hand, or 

 perhaps a fold of the serpent, may have come in contact with the hair. 



It has been stated that the group was found iu Rome in the year 

 1506. There is a curious letter, not generally known, but published 

 by the Abbate Fea, from Francesco da San Gallo to Monsignore 

 Spedalengo, dated 1567, in which the circumstances of the discovery 

 are alluded to. He says, " It being told to the Pope that some fine 

 statues were found in a vineyard near S. Maria Maggiore, he sent to 

 desire Giuliano de San Gallo (the father of the writer) to go and 

 examine them that Michel Angelo Buonarotti being often in their 

 house, San Gallo got him to go also ; and so," says Francesco, " I 

 mounted behind my father (in grappa a mio padre), and we went. We 

 descended to where the statues were ; my father immediately ex- 

 claimed, ' This is the Laocoon spoken of by Pliny.' They made them 

 enlarge the aperture or excavation so as to be able to draw them out, 

 and then, having seen them, we returned home to dinner." The group 

 of ' Laocoon and his Sons ' is now preserved among the treasures in 

 art in the museum of the Vatican at Rome. A very fine cast of it is 

 in the Greek court of the Crystal Palace, Sydenham. 



LAPIDARY WORK. The work of the lapidary is that of reducing, 

 shaping, grinding, and polishing small hard pieces of stone, especially 

 those which go by the names of gems or precious stones. Such stones 

 require different modes of treatment according to their hardness. The 

 diamond, sapphire, ruby, chrysoberyl, and zircon rank among the very 

 hardest ; the agate, amethyst, aquamarina, bloodstone, carnelian, car- 

 buncle, cat's-eye, chalcedony, chrysolite, chrysoprase, crystal, emerald, 

 felspar, flint, fluor-spar, garnet, granite, jade, jasper, lapis-lazuli, onyx, 

 opal, porphyry, quartz, sardonyx, serpentine, and topaz, though 

 differing much among themselves in hardness, may be considered as 

 occupying a sort of medium rank ; while a softer class of minerals 

 and vitreous substances is that which includes alabaster, cannel coal, 

 coral, enamel, glass, jet, lava, malachite, mother of pearl, satinstone, 

 steatite, &c. It is by means of small revolving wheels that these are 

 cut and polished by the lapidary. The wheels are of iron, lead, wood, 

 and other substances. For cutting, the edge of the wheel is sharp, and 

 is touched with moistened diamond powder, emery powder, or some 

 similar material; and the edge then acts like an exquisitely fine saw, 

 which works its way through the hardest gems when applied to it. For 

 polishing, the gem or stone is held more frequently against the side 

 of the revolving wheel, or else against buff-leather fixed to the edge of 

 a broader wheel. One of the most delicate examples of lapidary-work 

 ever executed was the shaping of the world-renowned Kok-i-noor, or 

 " mountain of light," the large diamond obtained by Queen Victoria 

 from the chief of the Punjab. This jewel, large and fine as it is, 

 was found to have been bad]" ~ut and facetted ; Professor Tennant 



