Z E Y 



[ 278 ] 



ZOO 



In Dr. Mantell's Geology of the South- 

 East of Fngland, a species of zeus, found 

 in the chalk, the zeus Lewesiensis, is 

 beautifully figured. This ichthyolite is 

 from six to eight inches long, and its 

 width is nearly equal to the length of the 

 body. Dr. Mantell. 



ZEY'TANITE. The name given by Werner 

 to the mineral ceylanite. See Ceylanite. 



ZI'GZAG. Having contrary windings and 

 turnings ; having short turns. 



ZINC. } (zink, Germ. Dr. Webster states 



ZINK. j[ that the common orthography of 

 this word, zinc, is erroneous ; it may be 

 so, but it is the customary and usual or- 

 thography of the best English writers.) 

 One of the fifty-five simple or elementary 

 bodies. A metal of a bluish-white co- 

 lour, with a fine {rrsnular fracture. Zinc 

 was not obtained in its metallic form till 

 the sixteenth century, though its ores 

 were known to the ancients, and used by 

 them in the formation of their brass or 

 bronze. It does not occur native ; its 

 most abundant ore is the sulphuret, called 

 Blende, common in most veins which 

 contain sulphurets of iron, lead, copper, 

 &c., in every country. The structure of 

 zinc is foliated. As regards its hardness, 

 it may be easily cut with the knife. Spe- 

 cific gravity from 6 - 9 to 7'2. It is mal- 

 leable, but its malleability is greatly in- 

 creased by heating it to a temperature of 

 300 Fahrenheit. By exposure to the air 

 it tarnishes and loses its lustre, but it is 

 but little oxidated. United with copper 

 it forms brass. The ores of zinc are few. 

 Its presence may be determined by roast- 

 ing the ore, and then fusing it by the 

 blow-pipe on charcoal with filings of pure 

 copper. If zinc be present, the copper 

 will be converted into brass. The ore 

 called calamine is a carbonate of zinc. 

 ZI'RCON. A mineral occurring in rounded 

 grains or fragments, or in regular crystals. 

 It is harder than quartz, and possesses 

 double refraction in a high degree. It is 

 transparent, or sometimes only translu- 

 cent. Specific gravity from 4*3 to 4-7. 

 Before the blow-pipe it is infusible, but 

 loses its colour. It may be distinguished 

 from garnet, idocrase, staurotide, &c., by 

 its int'usibility, specific gravity, and strong 

 double refraction. There are two varie- 

 ties of zircon, called zircon jargon and 

 zircon hyacinth. Zircon jargon consists 

 of zircoaia'69'0, silica 26'5, oxide of iron 

 0'5. Zircon hyacinth of zirconia 70*0, 

 silica 25-0, oxide of iron 0'5. The finest 

 specimens are brought from the island of 



- (Jfeylon. It occurs in primary and tran- 

 sition rocks, but is usually obtained from 

 the sand of rivers. 



ZIRCO'NIA. An earth, when pure, white 

 and tasteless, supposed to be a compound j 



of zirconium, its metallic basis, and oxy- 

 gen. An oxide of zirconium. 

 ZIRCO'NIUM. The metallic basis of the 



earth zirconia. 



ZO'DIAC. (zodiaque, Fr. zodiaco, It. zodi- 

 acus, Lat. wc)iaKt)C, Gr.) A broad cir- 

 cle or region in the heavens remarkable, 

 not from anything peculiar in its own 

 composition, but from its being the area 

 within which the apparent motions of the 

 sun, moon, and all the great planets are 

 confined. The centre of the zodiac is the 

 ecliptic, which is inclined to the equinoc- 

 tial at an angle of about 23 28', inter- 

 secting it at two opposite points, called 

 the equinoctial points. The zodiac ex- 

 tends 9 on either side of the ecliptic. 

 ZODI'ACAL. Pertaining to the zodiac, as 



the zodiacal constellations, &c. 

 ZOI'SITE. ?A mineral, thus named from 

 ZOI'ZITE. $ Baron Von Zois, its disco- 

 verer. A variety of Epidote, of a grey, 

 brown, or yellowish colour. 

 ZOOLO'GICAL. Pertaining to zoology. 

 ZOO'LOGIST. One who studies, or is versed 



in, the natural history of animals. 

 ZOO'LOGY. (from wov an animal, and 

 Xoyoc, discourse, Gr. zoologie, Fr. zoo- 

 logria, It.) That branch of natural his- 

 tory which treats of animals, their habits, 

 structure, classification, &c. Prof. Buck- 

 land says that the study of zoology has 

 become as indispensable to the progress 

 of geology, as a knowledge of mineralogy. 

 ZOO'LOGY, FOSSIL. That division of zoology 

 which treats of fossil animals. The exa- 

 mination of the fossil remains of a former 

 state of creation has demonstrated the 

 existence of animals far surpassing in 

 magnitude those now living, and brought 

 to light many forms of being which have 

 nothing analogous to them at present, 

 and many others which afford important 

 connecting links between existing genera. 

 ZOO'PHAGA. (from wov, an animal, and 

 tyayliv, to eat, Gr.) A tribe of animals 

 which attack and devour living animals. 

 The animals of this tribe have three kinds of 

 teeth, namely, cutting teeth, canine teeth, 

 and grinders ; their paws are armed with 

 claws ; their muzzle is often set with 

 whiskers, usually called smellers ; their 

 mammary organs are dispersed ; their in- 

 testines are less voluminous than those of 

 herbivorous animals. 

 ZOO'PHAGOUS. Attacking and devouring 



living animals. 



ZOO'PHYTE. (w60vra, from wov and 

 0uo>, Gr. qua mediae sunt nature inter 

 animalia etplantas ; zoophyte, Fr. zoojito, 

 It.) Animal plants, corals, sponges, and 

 other aquatic animals which have obtained 

 the name from an opinion formerly enter- 

 tained that they were intermediate be- 

 tween animals and vegetables. In conse- 



