Chap. 10.] LUXURY IN THE USE OF CRYSTAL. 395 



there is crystal, but that found upon the Alpine heights in 

 Europe is, in general, more highly valued. According to 

 Juba, there is crystal in a certain island of the Red Sea, oppo- 

 site the coast of Arabia, called " Necron ;" 63 as, also, in ano- 

 ther neighbouring island 6 * which produces the precious stone 

 known as the " topazus ;" where a block of crystal was ex- 

 tracted, he suys, by Pythagoras, the prefect of King Ptole- 

 inaMi?, no less than a cubit in length. 



Cornelius jiocchus informs us that in Lusitania, there have 

 been blocks of crystal found, of extraordinary weight, in sinking 

 shafts in the Ammiensian w mountains there, to u water-level 

 for the supply of wells. It is a marvellous fact, stated by Xeno- 

 crates of Ephesus, that in Asia and in the Isle of Cyprus, 

 crystal is turned up by the plough ; it having been the general 

 belief that it is never to be found in terrcous soils, and only 

 in rocky localities. That is much more probable which the 

 same Xenocrates tells us, when he says that the mountain 

 streams often bring down with them fragments of crystal. 

 Sudincs says, that crystal is only to be found in localities that 

 face the south, a thing that is known to be really the fact : 

 indeed, it is never found in humid spots, however cold the 

 climate may be, even though the rivers there freeze to the very 

 bottom. Kain. water and pure snow are absolutely necessary 

 for its formation, 84 and hence it is, that it is unable to enduro 

 heat, being solely employed for holding liquids that are taken 

 cold. From the circumstance of its being hexagonal 47 and 

 Lexahedral, it is not easy to penetrate this substance; and the 

 more so, as the pyramidal terminations do not always have 

 the same appearance. The polish on its faces is BO exquisite, 

 that no art can possibly equal it. 



CHAT. 10. LUXURY DISPLAYED IN THE USE '>p CRYSTAL. BEME- 



PI KS DERIVED FROM CRYSTAL. 



The largest block of crystal that has ver been beheld by 



53 The Island "of the dead." Brotcro supposes it to be the island of 

 Muccira. 



84 Sec B. vi. c. 34. As Ajasson remarks, there could be no snow or ice 

 Lcre. " See U. iv. c. 35. 



M Dioscoridcs attribute the hardening of crystal to the action of thesun. 



67 " Its shape is rhombohedral, and bcmihcdral in some of its modifica- 

 tions. The planes on the angles between the prism and pvramidal termi- 

 nations, incline sometinu-s to the right, and FOIU. times to the left, and the 

 crystals are termed right and lelt-huudcd crystals." Dana, System of 

 Mineralogy, Art. Quartz. . 



