SATIN-WOOD 753 



as its specific gravity and inferior hardness show. White sapphires are some- 

 times so pvuw, that when properly cut and polished they have been passed for 

 diamonds. 



The yellow and green sapphires are much prized under the names of oriental topaz 

 and emerald. The specimens which exhibit all these colours associated in one stone 

 are highly valued, as they prove the mineralogical identity of these varieties. 



Besides these shades of colour, sapphires often emit a beautiful play of colours, or 

 chatmement, when held in different positions relative to the eye or incident light ; and 

 some likewise present star-liko radiations, whence they are called star-stones or 

 asterias; sending forth 6 or even 12 rays, that change their place with the position of 

 the stone. This property, so remarkable in certain blue sapphires, is not however 

 peculiar to these gems. It seems to belong to transparent minerals which belong 

 to the rhombohedral system, and arises from the combination of certain conditions 

 in their cutting and structure. Lapidaries often expose the light-blue variety of 

 sapphire to the action of fire, in order to render it white and more brilliant ; but with 

 regard to those found at Expailly in France, fire deepens their colour. 



SARD. A variety of chalcedony of a dark reddish-brown colour, almost ap- 

 proaching to black by reflected light, and very deep red. inclining to blood-red, by 

 transmitted light. It is found under the same conditions as carnelian, but is rarer 

 and more highly esteemed, and therefore fetches a higher price. The name is 

 derived either from sarx (Gr. <rdp, 'flesh'), in allusion to its colour, or from Sardis in 

 Lydia, whence it is said to have been first brought. It should be remarked, however, 

 that the sard presents, in its interior and in the middle of its ground, concentric 

 zones, or small nebulosities, which are not to be seen in the red carnelian, properly so 

 called. The ancients certainly knew our sard, since they have left us a great many 

 of them engraved, but they seem to have associated under the title Sarda both the 

 sardoine of the French and our carnelians and chalcedonies. Pliny says that the 

 sarda came from the neighbourhood of a city of that name in Lydia, and from the 

 environs of Babylon. Among the engraved sards which exist in the collection of 

 antiques in the Bibliotheque Royale of Paris, there is an Apollo remarkable for hs 

 fine colour and great size. When the stone forms a part of the agate-onyx, it is 

 called sardonyx. 



SARDINE (Atherina ; Gr. adrip, ' a spine'). A genus of fishes, belonging to the 

 order Aoanthopterygii. They form a very extensive fishery in the Mediterraenan. 

 They are salted and preserved in oil, and are sent in large quantities to this country. 

 Eecently (1874) an establishment has been founded at Mevagissey in Cornwall for 

 preserving the small pilchards in the same way as the sardines of the Mediterranean 

 are prepared. It is thought by some that the sardine and the young pilchard are 

 identical, but the sardine is of the genus Atherina, whereas the pilchard belongs to 

 the ClupeidcB. 



SARDONYX. A variety of onyx, composed of alternate layers of sard and white 

 chalcedony. It much resembles agate, but the colours, usually a light clear brown and 

 an opaque white, are arranged in flat horizontal planes. Amidst the chalceclonic series 

 are various stones having the same general character, of mixtures of true quartz, 

 with opal disseminated. H. W. B. 



SATIN (Eng., Fr. and Ger.) is the name of a silk stuff, first imported from 

 China, which is distinguishable by its very smooth, polished, and glossy surface. It is 

 woven upon a loom with at least five-leaved healds or heddles, and as many corre- 

 sponding treddles. These are so mounted as to rise and fall four at a time, raising and 

 depressing alternately four yarns of the warp, across the whole of which the weft is 

 thrown by the shuttle, so as to produce a uniform smooth texture, instead of the 

 chequered work resulting from intermediate decussations, as in common webs. Satins 

 are woven with the glossy or right side undermost, because the four-fifths of the 

 warp, which are always left there during the action of the healds, serve to support 

 the shuttle in its race. Were they woven in the reverse way, the scanty fifth part of 

 the warp-threads could either not support, or would be too much worn by the shuttle. 

 See TEXTILE FABRICS. 



SATINET. A mixed fabric, woven to imitate satin. 



SATIN SPAR. A fibrous variety of gypsum (sulphate of lime); when 

 polished, used for ornamental purposes. It is sometimes a fibrous carbonate of lime. 

 SATIN-WOOD. A veneering wood of great beauty, the product of the Chlo- 

 roxylon Swietenia of India. The light colour and lustrous polish of the wood, com- 

 bined with the pleasing ' figure ' it exhibits, renders it a favourite wood for drawing- 

 room furniture. It is a native of Ceylon, and is found in the northern and southern 

 but chiefly in the eastern districts. Above all things, it requires the most careful 

 seasoning, for it is liable to warp and split ; and once let such a misfortune happen to 

 boards destined say for wardrobe-panels and the pecuniary loss is very great. Care 

 VOL. III. 3 C 



