A III US 



Of the sigr.s. Argument of t\e moon's 

 apogee, culled also the animal ar$vn;et, 

 the distance of the moon's apogee from the 

 Bun's place, that is, the are of the eclip- 

 tic comprised between these two points. 

 Argument of parallax, denotes the effect 

 produced by parallax on an observation, 

 and which is the argument for deter- 

 mining the quantity of horizontal pa- 

 rallax. 



AROCMENTUM AD UOMIXEM, nn argu- 

 ment which presses with consequences 

 drawn from one's OWE principles and con- 

 Cessions 



ARK 



AROUS-SHELL, a species of porcelain 

 shell, beautifully variegated with spots, 

 In some measure like the peacock's tail. 



AROTN'MS, a genus of butterflies, re 

 markable for the silvery spots on toe 

 under part of the body. 



AR'OYRITIS, an old tirjre of litharge, 

 from a.f'yv^of, silver, !>e- ausc s^jx'.ratedin 

 the process of extracting sib'tr from the 

 lead ores. 



ARG\n'ocoME,a sub-genus of cud- weed 

 (gnaphaiium). From e^yvfes: silver, and 

 KOftv,, hair, becau>* the tiowers are sil- 

 very white. 



A'Rii, in music, Ital. for air v q. v.) 



A'RIAWS, the adherents of the Alexan- 

 drian bishop. Arius, who held Christ to be 

 a created being, inferior to God in nature 

 and dignity. Their doctrine is Arianism. 



A' i is, Latin for ram. "La astronomy, a 

 constellation forming the first of the 

 twelve Bignsofthe zodiac. Symbol, cy> 

 In the ancient cjiiitary art, ones means 

 a battering ram. 



ARIET'TA,, in mutie, Italian for dim. of 

 aria (q. v-). 



A'BII., Lat. arillui. A tunic investing 

 the seed of eome plants completely or 

 partially. It is lixed at the base of the 

 seed, and mere or less closely envelope* 

 the other parts. Mace u t&e aril of the 

 nutmeg. 



Aaix'AXcs, ) The evil principle la the 



AHRI'MAN. j Persian theology, which 

 perpetually counteracts ibe designs of the 

 good principle, Ormuza or Horminda. 



ARIO'SO, Italian for light, lively. Ap- 

 pMed in music 10 8 kind of melody bor- 

 dering on the majestic style of a capital 

 air. 



ABI'STX, thf: awn. A sharp bristle-like 

 appendage which proceeds from the husk 

 or glume of grawfc. 



ARI'STATE, Lav tir-ts^uj, awned. Ap- 

 plied to leaves, &c. Terminating in a long 

 rigid spine, which docs not appear as a 

 contraction. 



ARISTOLO'CEIA, the plant birth wort. 

 Genus. Gynandria llcxandria. Name, 

 ttfirrtf, and >.o^ia, for its supposed me- 

 dicinal virtues. One indigenous species. 



Am:TOLOcHi'ia, a natural family of 



plants, of which the geuu Afisiolochia it 

 the type. 



ARISTOTE'LIA., the generic name of a 

 South American tree. Ifoilecandi-ia _1/o- 

 nogynia. Named in honour of Aristotle, 

 the ancient philosopher. 



ARITH'METIC, from u,fiGu,Y l nxv n the an 

 of numbering, a$i&fAo;, number. A branch 

 of mathematics which has for its object 

 the combination of numbers according to 

 certain rules, in order to obtain results 

 which satisfy given conditions. These 

 niles, methodically arranged, constitute 

 the science to which is given the name 

 arithmetic. Arithmetic is called theoreti- 

 cal when It treats of the properties and 

 relations of ji-jiubers considered abstract- 

 edly : and i-ructical, when it treats simply 

 of the art of computing. Integral arith- 

 metic treats of whole numbers ; fractional 

 arithmetic of fractional numbers ; decimcl 

 arithmetic of decimal numbers. Logatitr.- 

 wu'c arithmetic is that which is performed 

 by tables of logarithms. Political arith- 

 metic is the calculation of revenue, deter- 

 mination of taxes, adjustment of expendi- 

 ture, &c. Specious and universal arithmetic 

 are names given to algebra. All arith- 

 metical operations are performed bv 

 means of addition, subtraction, mul^'pli- 



cation, and division. Arithmetical c:i ,- 



plement of a number is what it wants of 

 the next higher decimal denomini*i - ji. 

 Thus 4 is the arithmetical complement o: 



6, as it is what 6 wants of 10. Arith- 

 metical mean between two numbers is a 

 number, such that its excess over the first 

 is equal to its defect from the second. 

 Thus 5 is an arithmetical mean between 

 3 and 7. Arithmetical progression, a se- 

 ries of numbers, such that each differs 

 from the quantity that precedes and fol- 

 lows it by the same number. Thus, 3,5, 



7, 9, form an arithmetical progression, 

 when the common difference of the terms 



is 2. Arithmetical projiortion of four 



numbers consists in the difference of the 

 first and second being equal to that of the 

 third jmd fouriii. Thus, 2, 5, 8, II. 



A*:rE*wcu. RATIO. The difference 

 of r. twt- of an arithmetical progression. 



A.i*. tiif. awn* jriven,in pur translation 

 c'f the Kiblt;, t-i the floating edifice in 

 M-hicn Noah r.si<ied during the deluge. 

 From Sax. CflC or Cflk, a chest. Lat. 

 area. Dut. arke. The chest in which the 

 tables of the law were preserved was 

 called the ark of the covenant. This coffer 

 was 3 feet 9 inches long, by 2 feet 3 

 inches in breadth and the same in depth. 

 It was made of shiitim-wood, and covered 

 with the mercy scat, or propitiatory 

 (IXatrir^n i-r^ica], made of pure gold, 

 and having at each comer a cherub with 

 expanded wings. 



