AMIANTHUS 



17 



AMNIOTA 



Amianthus, (am-i-an'thus). [Gk. amiantos, 

 pure.] A fibrous incombustible variety of 

 amphibole ; resembling silky threads : also 

 called mountain flax. 



Amici's compound microscope = Chevallier's 

 m.: an achromatic microscope, in which the 

 tube may be placed either vertically or hori- 

 zontal. 



Amidated acids, (a-mi-dat'ed). [Amides, q.v.] 

 = Amidic acids: compounds, derived from the 

 action of dibasic acids and the amides of the 

 acids, containing half of each constituent. 

 (Ex. 1 camphoric acid + 1 camphor amide 

 =2 camphoramic acid). Usually prepared by 

 the action of ammonia upon the dibasic acid. 

 Amides, (a'midz). [Ammonium and ide, ter- 

 mination.] Compounds derived from normal 

 ammonium salts by the removal of water. 

 Ex. Ammonic benzoate - water=benzamide. 

 Monamides = amides salts of monobasic 

 acids water. Diamides = salts of dibasic 

 acids -water. Triaraides=contain 3 atoms 

 of ammonia. The amides are also regarded 

 as ammonia, in which one atom of H is re- 

 placed by an acid organic radicle. 

 Amide bases, (a'mid). [Amides, g.v.]=Ami- 

 dogen bases =primary monamines: ammonia 

 in which one atom of H has been replaced 

 by a basic hydrocarbon. Ex. Aiuylia = 

 ammonia H + amyl. 



Amidic acids, (a'mi-dik). [Amide, q.v.]= 

 Amidated acids, q.v. 



Amidin, (a'mi-din). [F. amidon, starch]= 

 zCgHjoO5=the soluble portion of starch. 

 Amido, (a'mi-do). [Amide.] A prefix to the 

 names of many acids (such as amido-acetic 

 acid), in which one atom of the acid is re- 

 placed by an atom of amidogen. 

 Amidogen, (a-mid'o-jen). [Amide, q.v.; Gk. 

 gennao, I produce]=H 2 N: an hypothetical 

 compound = ammonia H = the base of 

 amides. A. baiet = primary monamines= 

 monammonias, q.v. 



Amiens valley gravel, (am'i-enz). [Near 

 Amiens in France.] Post-Pliocene beds, con- 

 taining mammal bones and flint instru- 

 ments. 



Amines, (am-Inz). [Amide, q.v.] Organic 

 bases=ammonia in which one, two, or three 

 atoms of H are replaced by one, two, or three 

 equivalents of hydrocarbon radicles. 

 Ammelid, (am 'me -lid). [Melam, q.v.] = 

 CgHgNcjC^: a white powder obtained from 

 melam. 



Ammeline, (am'me-lm). [Melam, q.v.]= 

 CsH^NjO: a substance of feeble basic pro- 

 perties obtained from melam. 

 Ammineae. (am-min'e-e). [Gk. ammot, sand.] 

 Umbelliferous plants, many growing in sandy 

 places, such as the goat-weed, celery, hem- 

 lock, &c. 



Ammodenia, (am-mo-de'ni-a). [Gk. ammoa, 

 sand.] A sub-division of Arenaria, contain- 

 ing the sea-purslane. 



Ammonia (am-mo'ni-a). [Sal ammoniac, q.v.] 

 =H 3 N=:volatile alkali=spirit of hartshorn: 

 a very pungently smelling colourless gas, 

 feebly combustible, and having strong alka- 

 line properties: combines with any acid, can 



be liquefied by a temperature of 40 F., and 

 frozen to white crystals by - 1 03 F. A. bases, a 

 group of organic bases, formed on the type of 

 ammonia : include Arnmouia=:H 3 N ; Phos- 

 phurreted H = H 3 P ; Arseniu retted H= 

 H 3 As; Antimoniuretted H=H 3 Sb, q.v. 



Ammonias, compound. Compounds having 

 the same properties with ammonia, and re- 

 sembling it in composition : may be con- 

 sidered as ammonia in which some of the 

 hydrogen is replaced by a compound radicle; 

 or as ether in which oxygen is replaced by 

 amidogen. 



Ammonia type. [Chemical types, g.v.]=Ni- 

 tride type: a type of chemical composition, 

 represented by H 3 N. 



Ammoniacal, (am-mon-i'ak-al). [Ammonia, 



q.v.] Resembling, or belonging to, ammonia. 



Ammoniacal liquor. A liquid formed during 

 the distillation of coal gas, in which the 

 nitrogen of the coal is combined with hydro- 

 gen, and forms ammonia. 



Ammoniacum, (am-mo-ni'a-kum). [Ammo- 

 nia, q.v.] = Ammoniac = gum ammoniac : a 

 gum resin obtained from some plants, Do- 

 rema ammoniacum, Ferula orientalis, <tc. 



Ammoniated salts, (am-md-ni-at'ed). Com- 

 pounds of metallic salts with ammonia; 

 usually anhydrous. 



Ammonic salts, (an i-nxln'i k). [Ammonia, q.v.] 

 =Salts of ammonium =chemical compounds 

 in which ammonium is the base. Ex. Chlo- 

 ride of ammonium = Ammonic chloride=- 

 H4NCl=Muriate of ammonia=Sal ammo- 

 niac. A product of coal-gas manufacture. 



Ammonides, (am'mo-nidz). [Ammonia, q.v.] 

 =Ammons: compounds of ammonia with 

 anhydrides of dibasic acids. Ex. Sulphuric 

 ammonide=(H 3 N>2SO 3 . 



Ammonio, (am-mo'ui-o). [Ammonia, q.v.] A 

 prefix to imply the presence of ammonia in 

 a compound. 



Ammonites, (am'mo-nitz). [L. cornu Am- 

 monis, old name. ] Fossil cephalopodous mol- 

 luscs of spiral form, found in all strata from 

 the palaeozoic to the chalk; very numerous, 

 varying greatly in size; all now extinct; 

 sometimes called snake-stones. 



Ammonitidae, (am-mon-It'i-de). [Ammonite, 

 q.v.] Fossil shells, of which the Ammonite 

 is the type. 



Ammonium, (am-m5'ni-um). [Ammonia, q.v.] 

 =H 4 N ; the hypothetical base of ammonic 

 salts, resembli ng in basic character the metals ; 

 produced by ammonia and water (=H 3 N+ 

 H 2 O) becoming H4NHO=ammonic hydrate. 



Ammonium bases, a group of organic bases, 

 all hydrated=ammonic hydrate H 4 NHO, in 

 which all four atoms of H are replaced by 

 four equivalents of one or more hydrocar- 

 bons. Ex. Hydrated tetramylium oxide= 

 (C 5 H n ) 4 NHO. 



Amnion, (am'ni-on). [Gk. amneios, lamb-like, 

 soft.] 1. The soft envelope, filled with fluid, 

 which encloses the embryo of a higher verte- 

 brate animal during its development. 2. 

 The envelope of the seed in plants. 

 Amniota, (am-ni-6'ta). [Amnion, Q.V.] Rep- 

 tiles, birds, and mammals, a division of Yer- 



