AG A 



AGO 



In grammar, a particle added to a word, 

 to diversify its form, or alter its significa- 

 tion ; as artful, wealthy, strengthew, con- 

 yulsion, &c. See Prefix. 



AFFLU'XUS {affluo, to flow to). Forma 

 specifica. Names given in former times 

 to a supposed reciprocal influence of ter- 

 restrial bodies ; it was compared to the 

 effect of a magnet on iron, and of amber 

 on chaff. 



AGA'LMATOLI'TE ( a-^aXixa, an 

 image, \i9o^, a stone). Bildstein, or 

 figure-stone. A massive mineral, of a 

 grey, brown, flesh-red colour, sometimes 

 spotted, or with blue veins. It has been 

 called steatite pagodite, from its being 

 carved by the Chinese into grotesque 

 figures. It is found at Naygag in Trans- 

 sylvania, and Glyderbach in Wales. 



AGA'MID^ {agama, the name of a 

 lizard). The first section, according to 

 Cuvier, of the Iguanian Sauria, charac- 

 terized by the absence of palatal teeth. 

 All the agamoid lizards possess the pro- 

 perty of changing their colour ; and from 

 this circumstance, perhaps, the name 

 (afajxai, to wonder at) is derived. 



A'GAMOUS (a, priv., idyuos-, mar- 

 riage). Sexless ; a term applied by some 

 botanists to what are more commonly 

 called cryptogamous plants, from the 

 notion that they possess no sexual cha- 

 racters—that they are absolutely destitute 

 of stamen and pistil. 



A'GARIC {Agaria, a kingdom of Sar- 

 matia). The generic name of the Mush- 

 room tribe of the Fungi which grow in 

 decaying animal or vegetable matter. 



AGARIC MINERAL. One of the 

 purest of the native carbonates of lime, 

 found in clefts of rocks, and named from 

 its resemblance to the agaric in texture 

 and colour. It has been considered as a 

 variety of meerschaum. The Germans 

 call it bergmehl, or mountain meal ; the 

 Italians, latte di luna, or moon-milk. It 

 is the argillo-murite of Kirwan, the talc 

 pulverulent silicifere of Haiiy. 



AGA'STRICA (a, priv., yaari]?, the 

 stomach). Stomach-less ; a term applied 

 to certain animalcules, which were sup- 

 posed to be devoid of internal digestive 

 cavities. 



A'GATE ('Ax«t;i9, the name of a river 

 in Sicily). A genus of semi-pellucid 

 gems, consisting of a basis of chalcedony, 

 with variable proportions of jasper, ame- 

 thyst, quartz, opal, heliotrope, and cor- 

 nelian. The finer varieties are termed 

 oriental ; the most beautiful British spe- 

 cimens are known by the name of Scotch 

 12 



pebbles, and sometimes, from their local- 

 ity, Cairtigorms. 



1. Ribbon agate consists of alternate 

 and parallel layers of chalcedony with 

 jasper, quartz, or amethyst. The most 

 beautiful specimens come from Siberia 

 and Saxony. It occurs in porphyry and 

 gneiss. 



2. Brecciated agate consists of a base 

 of amethyst, containing fragments of 

 ribbon agate. It is of Saxon origin. 



3. Fortification agate is found in no- 

 dules of various imitative shapes, im- 

 bedded in amygdaloid. This occurs at 

 Oberstein on the Rhine, and in Scotland. 

 On cutting it across, and polishing it, 

 the interior zig-zag parallel lines bear a 

 considerable resemblance to the plan of a 

 modem fortification. In the very centre, 

 quartii and amethyst are seen in a splin- 

 tery mass, surrounded by the jasper and 

 chalcedony. 



4. Mocha stone is a translucent chal- 

 cedony, containing dark outlines of ar- 

 borization, like vegetable filaments, sup- 

 posed to arise from mineralized plants of 

 the cryptogamous class. It is found in 

 Arabia. 



5. Moss agate is a chalcedony with va- 

 riously-coloured ramifications of a vege- 

 table form, occasionally traversed with 

 irregular veins of red jasper. In this 

 and the preceding species, aquatic con- 

 fervae have been discovered, lire. 



A'GGREGATE {aggregatus, herded 

 together). 1. A term applied in physics 

 to a body or mass composed of smaller 

 bodies or masses. The smallest parts 

 into which an aggregate can be divided 

 without destroying its chemical proper- 

 ties, are called integrant parts. 2. Ag- 

 gregate animals are animals clustered 

 together in a common enveloping organ- 

 ized substance, as the polypes, the aca- 

 lephae, and the acephalous mollusca. 

 3. In botany, the term is applied to 

 parts which are crowded together, as the 

 florets of the compositae, the carpels of 

 ranunculaceae, &c. 



AGO'MPHIA (a, priv., -yo/i^of, a 

 grinder). Toothless animals ; a term 

 applied by Ehrenberg to those rotifera 

 whose jaws are deprived of teeth. 



AGO'NIC LINES (a, priv., ya)i/*'a, an 

 angle). The name given by Prof. August 

 to some lines existing on the surface of 

 the earth, on which the horizontal needle 

 points to the true north ; in other words, 

 where the magnetic meridian coincides 

 with the geographical. These lines of no 

 declination are two in number: one, 



