A M M 



02 



AMN 



AM'MI, Bishop' s-weed, a genus of umbel- 

 liferous plants of four species. Class pen- 

 tandria, order digynia. "Warm climates. 

 Name, from a,fj,/M>s, sand, in reference to 

 the appearance of its seeds, which are 

 used extensively as an ingredient of tne- 

 riaca. 



AMMITE, from ot-f^tM?, sand, and X/0?, 

 stone, sand-stone ; the roe-stone or oolite 

 of recent authors. 'Written also Hammite. 



AMMO'BATES, a genus of honey-making 

 bees (apiarian). They belong to the Cttcti- 

 lines of Latreille. 



AMMOCHRY'SE, K^fM^uffo;. A yellow 

 soft stone found in Germany. In the time 

 of Pliny it was used, when ground to 

 powder, to strew over writing like black 

 sand with us. It is probably a micaceous 

 sulphuret. 



AM'MODYTE, the sand-eel. The ammo- 

 dytes belong to the order malacopterygii 

 apodes of Cuvier. The name is also com- 

 mon to a small African serpent of the 

 viper tribe, and to a large venomous ser- 

 pent of Ceylon. 



AM'MON, the title under which Jupiter 

 was worshipped in Libya. " Ammon was 

 originally a Libyan deity adopted by the 

 Greeks."" The name seems derived from 

 u.[*,S, sand, and the situation of the 

 celebrated temple, in an oasis surrounded 

 by desert, further justifies this etymology. 



AMMONACEA, according to the arrange- 

 ment of De Blainville, a family of the 

 order polythalamacea : it embraces the 

 genera discerbis, scaphites, ammonites, 

 undsimplegas. In the Lamarckian system, 

 the ammonacea is a family of the order 

 polythalamous cephalopoda, embracing 

 the genera of ammonites, ammonoceras, 

 baculites, and turrilites. 



AMMO'NIA, a chemical compound, other- 

 wise called the volatile alkali, and which, 

 in an uncombined state, and under ordi- 

 nary atmospheric pressure, exists in the 

 state of a highly pungent gas, possessing 

 all the mechanical properties of air, but 

 very condensable in water, with which it 

 forms the water of ammonia, aqua-ammo- 

 nia, or spirit of hartshorn of the shops. It 

 is called ammonia from its being chiefly 

 obtained from sal ammoniac ; volatile al- 

 kali, from its being an alkaline gas ; harts- 

 horn, from its having been originally 

 obtained by distillation from the horn of 

 the hart. Its constituents are three vols. 

 hydrogen, and one vol. of nitrogen, con- 

 densed into two vols. By strong com- 

 pression it becomes a liquid of sp. gr. 76. 



AMMO'NIAC, gum-resin, the inspissated 

 juice of an umbelliferous plant (the do- 

 rema armeniacum) which grows in Persia. 

 It possesses a fetid smell and bitterish taste. 

 It is imported in large masses, composed 

 of small whitish tears. It is used in me- 

 dicine, and in making the substance 



called diamond cement. It is called also 

 gum-ammoniac, and is latinised ammonia- 

 citm. Pliny says that it takes its name 

 from its being produced in the vicinity of 

 the temple of Jupiter .'uamon in Africa. 



AM'MOXITE, snake-stone, or serpent-stone, 

 or cornu-Ammonis. The Ammonites con- 

 stitute an extensive genus of fossil shells, 

 allied to the Nautili, which inhabit cham- 

 bered shells curved like a toiled snake. 

 They are very abundant in the strata of 

 the secondary mountains, varying from, 

 the size of a lentil to that of a "coach- 

 wheel. M. Krochant enumerates 270 spe- 

 cies. They appear to have been almost 

 xiniversally distributed in the ancient 

 world. They are found at an elevation 

 of 16,000 feet on the Himalaya Mountains, 

 and are so plentiful in some parts of 

 Germany as to be broken for mending 

 roads. They belong to the cephalopodous 

 order of Mollusca, and take their name 

 from their resemblance to the horns on 

 the statues of Jupiter Amm-in. 



AMMONI'TIDJE, a family of Cephalopoda, 

 with chambered syphoniferous shells, and 

 distinguished from the other Ammonites 

 by the septa being sinuous. 



AMMO'NICM. Sir H. Davy gave this name 

 to what he believed to be the metallic 

 basis of ammonia. According to the hy- 

 pothesis of Berzelius, ammonium consists 

 of 1 vol. of nitrogen and4 vols. of hydrogen. 



AMMO'NITRET, a compound of ammonia 

 and any substance not acid, as a metallic 

 oxide. 



AMMONOCB'RAS, ) From Ammon, and 



AMMONOCE'RATITES. / xi%a;, a horn. 

 Ammon's-horn, a genus of fossil shells 

 resembling the Ammonites in their in- 

 ternal structure; but they are simply 

 curved, instead of being spirally con- 

 volute. 



AMMO'PHILA, sea-reed, marum, or mat- 

 weed. A genus of the class triandria, and 

 order digynia. Named from OC.[&/IAO;, sand, 

 and iftXof , a lover ; in allusion to its being 

 generally found on sandy sea-shores ; in 

 consequence of which habit, it is exten- 

 sively employed in Norfolk and Holland 

 for preserving the banks of sand which 

 protect those countries from the inroads 

 of the sea. 



AM'NION, AM'NIOS. The membrane of 

 the ovum, which immediately surrounds 

 the foetus : it lines the chorion, covers 

 the placenta, and is reflected on the um- 

 bilical cord, which it invests as far as the 

 umbilicum, where it terminates. From 

 otfMtov, which primarily meant a vessel 

 for receiving the blood of the victims at 

 sacrifices, and came afterwards to mean 

 the membrane described. 



AM'NIOS. In botany, a thin, seniitrans- 

 parent, gelatinous membrane, in which 

 the embryo of a seed is suspended wlieu 



