ALTAZIMUTH 



15 



AMALGAMATION 



Altazimuth, (al-taz'i-muth). [From altiinde 

 and azimuth.] An instrument for measur- 

 ing both the altitude and azimuth of a 

 star, &c. 



Altered strata. Those that have been modi- 

 fied, since their deposition, by heat, mois- 

 ture, and other forces 



Alternation of generations. The phrase used 

 to express the recurrence of similar char- 

 acters in every second or third generation 

 only: obtains in some species of every kind 

 of invertebrate animaL 



Althsea, (al-the'a). [Gk. altho, I heal.]= 

 Marsh mallow, hollyhock, &c. : an herb with 

 green petals and downy stem, belonging to 

 Malvaceae. 



Althionio acid, (al-thl'on-ik). [^looboL q.v., 

 and Gk. theion, sulphur.] = C 2 H 6 SO 4 : a 

 crystalline substance obtained by the action 

 of sulphuric acid on alcohol. 



Altica, ( al'ti-ka ). [Gk. altikos, active.] = 

 Garden flea: an insect. 



Altimeter, (al-tim'e-tor). [L. altus, high; 

 metrum, measure.] An instrument for 

 measuring heights. 



Altingiacese, ( al-ting-i-a'se-S ) = Liquidam- 

 bars: trees belonging to Amentales. 



Altitude, (al'ti-tude). [L. altitudo, height.] 

 The height of a star, &c., above the horizon, 

 measured by the angle of a vertical circle 

 passing through both. 



Alto-relievo, ( al'to-r5-15'vo ) = High relief; 

 sculptures in which figures are connected 

 with a background, but are partially de- 

 tached. 



Altrices, (al-tri'ses). Term used by Owen for 

 a sub-division of birds, including the flying 

 birds: Raptores, Scansores, Voli tores, and 

 Cantores. 



Alum, (al'um). [L. alume.n, alum.]=Potas- 

 Bio-aluminic sulphate=;KA12SO4-12H2O : A 

 colourless crystalline acid substance, formed 

 naturally by the action of sulphuric acid of 

 volcanoes upon potassium and aluminum ; 

 also obtained from alum schist : much used 

 in dyeing, painting, &c. 



Alums. Double sulphates, of which alum is 

 the type. 



Alum battery. A galvanic battery consist- 

 ing of carbon and zinc (unamalgamated) in 

 sand moistened by a solution of alum in 

 water : is constant for two years. 



Alum-bay beds=Lower Bagshot. 



Alum root = Geranium maculatum, the root 

 of which contains alum. 



Alum slate = Alum schist = alum ore. A 

 bluish-grey rock, chiefly silicate of alumina, 

 from which alum is obtained. 



Alum stone. A rock containing alum, gene-i 

 rally found in volcanic districts. 



Alumina, (al-u'min-a). [L. alumen, alum.]= 

 AloO3=alumine=:oxide of aluminum; the 

 basis of all clays : corundum, emery, ruby, 

 and sapphire, are varieties of alumina. 



Alumina group of minerals : Includes corun- 

 dum, sapphire, ruby, &c., varieties of anhy- 

 drous alumina. 



Aluminate group of minerals, (a-lii'mi-nat). 

 [Alumina, %.v.] Jncludes spinel, pleonaste, 



balas-ruby, &c., varieties of alnminate of 

 magnesium, with admixture of other metals. 



Aluminic, (al-u'mi-nik). Containing aluminum 

 as the base of a compound. 



Aluminite, (a-lu'mi-nit). [Alumina, q.v.]= 

 Websterite: a white opaque mineral, chiefly 

 hydrated sulphate of alumina. 



Aluminium, (al-u-min'i-um). [Alum, q.v.]= 

 Aluminum, q.v.: one of the earth-metals. 



Aluminium bronze. An alloy of 1 part alumi- 

 nium with 9 parts of copper. 



Aluminous cake, (a-lu'min-us). A sulphate 

 of alumina, prepared from china clay and 

 sulphuric acid; used as a cheaper substitute 

 for alum in manufactures. 



Aluminum, (al-u'min-um). [Alum, q.v.]Al'": 

 a white, malleable, sonorous metal, but little 

 acted upon by oxygen, which is the base of 

 all clay rocks. 



Alunite, (a'lu-mt). [F. alun, alum.]=Alum 

 stone, q.v. 



Alunogen, (al-u'no-jen). [F. alun, alum; Gk. 

 gennao, I produce.] A white fibrous mineral, 

 frequently found on the walls of mines and 

 quarries; chiefly hydrous sulphate of alu- 

 mina: also called feather alum, and hair 

 salt. 



Aluta, (a-lu'ta). [ L. aluta, soft leather. ]= 

 Leather stone : a mineral somewhat resem- 

 bling leather in appearance. 



Alveolar border, ( al-ve'o-lar ). [L. alveolus, 

 a little cell.] The bone bordering the jaw, 

 into sockets in which the teeth are fitted. 



Alveolar plates, (al-ve'o-lar). [L. alveolus, 

 a little cell.] Bony plates to which teeth 

 are fastened by anchylosis. 



Alveoli, ( al-ve'o-li ). [L. alveolus, a little 

 hollow.] Cavities in jaw- bones of animals, 

 in which the teeth are fixed. 



Alveolitidse, (al-ve-o-lit'i-de). [L. alveolus, a 

 little cell.] A group of tabulate corals, in- 

 cluding alveolites and ccenites. 



Alveolus, (al-ve'o-lus). [L. alveolus, a littlo 

 cavity.] Singular of Alveoli, q.v. 



Alwaida, (al-wa'da) = /3 Draconis : a star in 

 the constellation Draco. 



Alyssidae, (a-lis'i-de). [Alyssum, q.v.] A sub- 

 division of Pleurorhizeaj (Brassicaceae), in- 

 cluding whitlow grass, scurvy grass, &c., said 

 to have been used as a cure for hydrophobia. 



Alyssum, (a-lis'sum). [Gk. a, not; lysso, I 

 am mad. ]= Mad wort v. Alyssidaj. 



Amaoratic, (am-a-krat'ik). [Gk. hama, to- 

 gether; kratos, strength.] A lens so arranged 

 as to collect all the rays of light falling on 

 it into one focus. 



Amadou, (am'a-do). [The F. name: L. ad, to; 

 manus, hand: dulce, soft.] German tinder: 

 a, spongy inflammable substance prepared 

 from the fungus Boletus by its being steeped 

 in saltpetre. 



Amalgam, (a-mnl'gam). [Gk. hama, with; 

 gameo, to join.] An alloy of two or more 

 metals, of which one is mercury. 



Amalgamated zinc, ( a-mal'gam-at-ed )=zinc 

 coated with mercury. 



Amalgamation, (a-mal-gam -a/shun). [Amal- 

 gam, q.v.] The combination of any other 

 metal with, mercury; especially used for the 



