141 



AMAZON-STONE. 



AMETHYST. 



142 



Lily and Guernsey Lily, the showy Bruusvigias and Blood-Flowers 

 (Hamanthus) of the Cape of Good Hope, and the American Aloe belong. 

 They are characterised by having six stamens, a highly-coloured flower, 

 and an inferior ovary. The beauty of their blossoms serve as a cloak 

 to their poisonous properties, and shows how little the external 

 appearances of plants are to be trusted in judging of their virtues. 

 To form an opinion only from their aspect, these would be pronounced 

 the most harmless of plants, while in fact their bulbs are dangerous 

 poisons. The juice of that of Uimanthu* toxitarius is inspissated by 

 the Hottentots, who smear their arrow-heads with it ; other kinds 

 are not less fatal, and even the common daffodil and snowdrop contain 

 within their bulbs an acrid irritating principle which renders them 

 emetic. Like many other poisonous families, this occasionally secretes 

 a kind of fcecula, or flour, which, when separated from the juice that 

 is naturally mixed with it, becomes a wholesome article of food. The 

 arrow-root of Chili is yielded by an Alstromeria, which belongs to 

 A ma ryllidacece. 



The species, which are chiefly scattered over Brazil, Africa, and 

 tropical Asia, are nearly all bulbous ; a few only acquire a high degree 

 of development, and lose their bulbous character, as the Doryanthes, 

 Agave, and Littcea. [AGAVE.] 



AMAZON-STONE, in Mineralogy, a green variety of Felspar. 

 [FELSPAR.] 



AMBER, a carbonaceous mineral which occurs in beds of lignite, 

 in Greenland, Prussia, France, Switzerland, and some other countries. 

 The greater portion of it comes from the southern coasts of the Baltic 

 .Sea, where it is thrown up between Konigsberg and Memel. (Ber- 

 zelius, ' Traitd de Chimie,' vi. 589.) 



It is also stated (' Annales de Chimie/ xvi. 215) that it is obtained by 

 mining at a distance of 200 feet from the sea, and at a depth of about 

 100 feet, and is found in small cavities. It is occasionally met with 

 (Aikin's ' Diet, of Chemistry,' i. 57) in the gravel beds near London, 

 in which case it is merely an alluvial deposit. Amber occurs generally 

 in small pieces, which are sometimes colourless, frequently light- 

 yellow or deep-brown, and very commonly translucent; two large 

 masses have, however, been found, one of them weighing upwards of 

 thirteen pounds, and the other more than eighteen. 



Amber is rather harder than common resins, which it resembles 

 in several properties : it is susceptible of a good polish, and when 

 rubbed becomes electrical ; indeed the word electricity is derived from 

 $\(KTpoi>, the Greek name for amber. Its density varies from 1'065 

 to 1-U70. When bruised it exhales a slight aromatic odour ; and when 

 heated to 448 Fahrenheit it melts, inflames, burns with a bright 

 flame, and emits a smell which is not disagreeable. 



The subject uf the origin of amber is one which has been much 

 discussed. According to Berzelius (' Chimie,' vi. 589), it was origi- 

 nally a resin dissolved in a volatile oil or natural balsam. The proofs 

 of this opinion are, he conceives, numerous. Thus, it has often the 

 impression of the branches and bark upon which it lias flowed and 

 solidified ; it often contains insects, some of which are so delicately 

 formed, that they could not have occurred except in a very fluid mass. 

 I )r. Brewster (' Edinburgh Phil. Journal,' iv. 332) concludes, from an 

 examination of the optical properties of amber, that it is an indurated 

 vegetable juice. 



Amber consists of a mixture of a volatile oil, two resins soluble 

 in alcohol and in ether, succiuic acid, and a bituminous body that 

 resists the action of all solvents, and which is the principal part of 

 amber. 



Water does not act upon this substance ; it does not even dissolve 

 any of the succinic acid. Alcohol takes up a soft, yellow, limpid 

 r -in. Cold concentrated sulphuric acid dissolves amber ; thesolution 

 has a brown colour, and when water is added to it, the greater part 

 of the amber is precipitated. Nitric acid converts it into a resinous 

 substance, and dissolves it totally. 



When amber, in the state of fine powder, is boiled in a solution 

 of potash, a great quantity of succinic acid is dissolved. 



According to Drapiez, the composition of amber is as follows : 



Carbon 80'59 



Hydrogen 7'31 



Oxygen 673 



Asheg 3-27 



2-10 



100-00 



Tin- ashes consist of lime, silica, and alumina. This analysis can only 

 be considered .IHIUI approximation. 



.\Tiil>er is emploped for ornamental purposes, in the manufacture 

 ot necklaces, Ac. It is used also for preparing amber-varnish, for 

 ol. (.lining a peculiar oil used in medicine, and it yields succinic acid 

 emyloyed in chemical investigations. 



AMHERGRIS, a substance of animal origin, found principally in 

 warm climates, floating on the sea, or thrown on the coasts. The 

 best comes from Madagascar, Surinam, and Java. It has been found 

 in tlic intestinal canal of the 1'hyseter macrocejihalus, mixed with the 

 remains of several marine animals which have served it for food. On 

 tlii* account it has been supposed to be a morbid product, analogous 

 to biliary calculi 



Ambergris of good quality is solid, opaque, of a bright gray colour) 

 which is darkest externally, and intermixed with yellow or reddish 

 striae. When it is heated or rubbed, it exhales an odour which is 

 agreeable to most persons. It is sufficiently soft to be flattened 

 between the fiugers. Its fracture is fine-grained, with traces of 

 lamellar structure. The heat of the hand is sufficient to soften it. 

 Its specific gravity varies from O'OOS to 0'920. 



When ambergris is heated with boiling alcohol of the specific gravity 

 0'833, until it is saturated, a peculiar substance, called Amltrein, is 

 obtained as the solution cools, grouped in mammillatcd, small, 

 colourless crystals. The solution, by evaporation, yields a further 

 portion of ambrein, which may be rendered pure, by being redissolved 

 in alcohol, and then crystallised. 



Ambrein, thus obtained, is brilliant, white, and insipid ; it has an 

 agreeable odour, which appears, however, to be adventitious, because 

 it is diminished by repeated crystallisations ; by fusion or a long- 

 continued gentle heat it acquires a resinous odour. Nitric acid con- 

 verts it into a peculiar acid, called Ambreic A cid. The caustic alkalies 

 do not form soap with it. 



According to Juch and Bouillon-Lagrange, benzoic acid exists in 

 distilled ambergris ; by the analysis of John, ambergris appears to lie 

 composed of ambrein 0'85, an extractive matter soluble in alcohol, 

 and probably containing benzoic acid, 0'025 ; watery extract with 

 benzoic acid and common salt, O'OIS ; with O'll not accounted for. 



Ambergris is used as a perfume ; and as the alcoholic solution is the 

 most odorous preparation of it, it is generally employed in that form. 



AMBLIGONITE, a mineral, consisting of phosphate of alumina 

 and lithia. It has a greenish-white colour, and ocelli's both massive 

 and in rhombic prisms. It is found at Chursdorf, near Penig, in 

 Saxony, and at Avendal in Norway. The cleavage is parallel to 

 the sides of the prism. It has an uneven fracture, and in thin 

 lamina; is translucent or transparent. The following is the analysis 

 of Berzelius : 



Phosphoric Acid 54'12 



Alumina 38'96 



Lithia 6'92 



100-00 



AMBLYSE'MIUS (Agassiz), a Fossil Fish, from the Oolite of 

 Northamptonshire. 



AMBLYU'RUS (Agassiz), a genus of Fossil Fishes, from the Lias 

 of Somersetshire. 



AMBURIA, a genus of plants belonging to the natural order 

 Chenopodiacew, several of the species of which yield volatile oils that 

 are employed as medicines in the countries where they grow. 

 A. anthdmintica is a native of North America, and its oil is extracted 

 and used as an anthelmintic under the name of Worm-Seed Oil. 



AMELANCHIER (the Savoy name of the Medlar), a genus of 

 plants belonging to the sub-order Pomece (Pomacecr, Lindley), of the 

 order Rosacete. It has a 5-cleft calyx with lanceolate petals, and an 

 ovary of 10 cells, with asolitary ovule in each. The mature fruit is 3-5- 

 celled, with one seed in each cell. The species are small trees, with 

 simple serrated deciduous leaves, and racemes of white flowers. 



A. vulfjara, the common species, is a native of rugged places 

 throughout Europe. It is the Avonia rotundifolia of Persoon. 



A. Botryapium, the Grape-Pear or Canadian Medlar, is a very com- 

 mon plant in Canada ; it is also a native of Newfoundland, Virginia, 

 and the higher parts of Columbia. It is a shrub 6 or 8 feet in height, 

 with a purple fruit. 



A. ovalis is also a shrub 6 or 8 feet high, and is a native of North 

 America, throughout Canada from Lake Huron to the Saskatchewan 

 and Mackenzie rivers, and as far as the Rocky Mountains. Sir John 

 Richardson says that it " abounds on the sandy plains of the Sas- 

 katchewan. Its wood, named by the Crees Meesass-quat-ahtick, is 

 prized for making arrows and pipe-stems, and is thence termed by 

 the Canadian voyageurs ' Bois de FISche.' Its berries, about the size 

 of a pea, are the finest fruit in the country, and are used by the Crees 

 under the name of Meesasscootoom-meena, both in a fresh and dried 

 state. They make a pleasant addition to pemmican, and excellent 

 puddings very little inferior to plum-pudding." 



Another North American species is known by the name of A. 

 sanguined. Its fruit is of a blood-red colour. 



(Don, Dichlamydeous Plants.) 



AMENTA'CE^E, a name sometimes given to a group of plants, 

 chiefly forest-trees, found in the north of Europe, Asia, and America ; 

 the flowers of which are arranged in a dense cylindrical deciduous 

 spike, called by botanists an Amentum. Such are the poplar, the birch, 

 the hazel, the willow, the oak, and many others. But as these genera 

 are in fact constructed in very different manners, Amentacete are more 

 correctly separated, by modern botanists, into several different orders. 

 [CoRYLACEM ; SALICACE.E ; BETULACE*, &c.] 



AMETHYST. This name has been applied to two precious stones 

 of ewentially different natures. The Oriental Amethyst is a rare 

 variety of Adamantine Spar [ADAMANTINE SPAR] or Corundum. The 

 Occidental, or Common, Amethyst, now to be described, is a variety 

 of quartz or rock crystal, which is met with in many parts of the 

 world, as India, Siberia, Sweden, Germany, Spain, &c. It occurs 

 in various forms, as massive, in rounded pieces, and crystallised. The 



