A L U M A. M A 11 Y L L I D E M. 



81 



ALUM. A mineral salt, much employed in the 

 useful arts. The minerals that afford alum either 

 contain it ready formed, or they contain its constituent 

 parts, which are disposed to unite and form alum, 

 when placed under favourable circumstances. This 

 latter is the most frequent case. It is found in 

 each of the great divisions of our globe, and occurs 

 as an efflorescence, or in delicate curved and pa- 

 rallel fibrous concretions ; also crystallised in octa- 

 hedrons and cubes. 



Alum mines are said to have been first found in 

 Italv, in 1460 ; and in the sixteenth century the 

 process of alum-making was commenced in Ger- 

 many and Spain, and a little before its conclusion 

 works were established at Whitby, in England, by 

 sir Thomas Chaloner. King James L, by advice of 

 his ministry, assumed the monopoly of it himself, 

 and therefore prohibited the importation of foreign 

 alum ; and in 1625 the importation of it was further 

 prohibited by a proclamation of Charles I. 



Alum is manufactured near Glasgow, from slaty 

 clay, which is obtained from old coal pits ; the slate 

 contains also iron pyrites, and both its constituents 

 combining with oxygen, sulphate of iron is formed, 

 with excess of sulphuric acid, which acting upon 

 and combining with the clay or alumina of the slate, 

 forms a double sulphate or ferro-sulphate of alumina, 

 which crystallises in small filaments of a greenish white 

 colour. When the slate containing this double salt 

 is put into water, it is dissolved ; by evaporation, 

 crystals of sulphate of iron are obtained ; and to the 

 solution, which is principally sulphate of alumina, 

 potash is added, and crystals of salt are formed ; 

 these are purified by re-dissolving them in water and 

 crystallisation. By exposing to air and moisture the 

 slate which remains after the solution of the sulphate 

 of iron and alumina, a further portion of the pyrites is 

 acted upon, and more sulphate of iron and alumina 

 are obtained, which are dissolved, as before, in water. 



ALUTERES. A genus of fishes belonging to Cu- 

 vier's order of Plcctogtiathcs, (plaited lipped fishes) and 

 the family Sclerodermcs, or hard-skinned. They have 

 the body long, slender, and compressed ; the muzzle 

 produced, pointed, and ending in a small mouth, with 

 about eight teeth in each jaw. Their first dorsal fin 

 has only one ray, which gives if the worm-like ap- 

 pearance on which the generic name is founded 

 There are several species noticed by authors ; but 

 very little is known of the habits of any of them 

 They are pelagic fishes, with large air bladders ; and 

 like the file-fish (batistes) which they resemble in 

 their more general characters ; they arc understood 

 to be pernicious at all events/they are not eaten. 



ALVEOLITES. A genus of zoophytes, the 

 major part of the species of which are known only in 

 the fossil state. They are closely allied to the coral- 

 lines. Four species are enumerated, three of which 

 have as yet been found only in the fossil state. 

 They are to be met with in the environs of Dussel- 

 dorf and Dax. They very rarely occur in this country. 

 Specimens referred by Parkinson to two of the spe- 

 cies, the incrustans and suborbicularis, are described 

 by him ; the one as imbedded in flint, the other in a 

 mass of Portland oolite. 



AMARANTHACE^E. A natural order of dico- 

 tyledonous plants, 'the characteristics of which are : 

 stamens situated below the ovarium, or seed vessels, 

 sometimes abortive ; anthers, one or two-celled ; 

 calyx, three or four-leaved, persistent, occasionally 



NAT. HI.,T. VOL. I. 



with bractese at the base ; fruit in a membranous 

 bladder ; seed?, lentiform, pendulous, having a hard 

 brittle shell ; leaves, simple, opposite or alternate, 

 without stipulae : flowers, scabrous, in heads or spikes, 

 usually coloured, generally hermaphrodite, pubes- 

 cent, simple, the hairs divided by partitions. 



AMARANTJICS PXVICULATL s. a, barren flower, bearing sta- 

 mens only; b, fertile flower, bearing pistils only; r, stamen; 

 d, trait bursting its envelope; e, vertical section of tiie seed 

 (magnified); /, the embryo ditto. 



Iii the young plants of this order the leaves are of 

 a soft, lax texture ; the seeds farinaceous, consisting 

 chiefly of starch and mucus ; their virtues are nutri- 

 tive ; and some of them, particularly the root of Gom- 

 phrena qfficmalu, arc tonic and stimulant. The ama- 

 ranth, from which the order derives its name, arc 

 herbaceous plants, generally annuals, the flowers of 

 which form in bundles at the top of the stalk. The 

 species are very numerous, and are very generally 

 dispersed over both hemispheres, increasing as the 

 distance from the equator increases. Some of the 

 plants belonging to the order are beautiful ornaments 

 in the flower-garden, and much cultivated for the 

 graceful and pendulous masses of their flowers. 



AMARYLLIDEJ2. An order of Monocotyle- 

 donetz, and the hundred-and-ninetieth order of the 

 natural system. It comprises thirty genera, and 

 four hundred and sixty-four species, of which last 

 there are as many varieties. Some cf the most splendid 

 of these will be found in the accompanying plate, of 

 which the following is a description : 



Ciiuunt giganteum. Few plants surpass this in 

 the majestic beauty of its flowers. It is known to 

 gardeners by the name of the Cape Coast Lily, and 

 was brought, about fifty years since, from the south- 

 western coast of Africa, of which it is a native, and 

 where it is highly prized by the natives ; being worn 

 as a charm to preserve them in war, and guard them 

 from pestUence. 



Amaryllis formosissima. This flower, as its trivial 

 name indicates, is the fairest of its tribe. It is pro- 

 pagated by offsets, which may be taken oft* every 

 year ; the best time to shift and part these roots is 

 in August, that they may take good root before 

 winter. They should be planted in pots of a middling 

 size, filled with light kitchen garden earth ; and if 

 they are kept in a moderate degree of warmth, they 

 will produce their flowers in plenty from March to 

 the beginning of September. 



Amaryllis belladonna. Is generally considered to 

 be a native of the Brazils. It is now, however, com- 

 mon over the whole of the European continent, 

 particularly in Spain and Italy. Seedsmen receive 

 the bulbs yearly in abundance from Portugal, and 

 these, when planted close to the foot of a southern wall, 

 will blow annually, after they are once settled, which is 

 not till after the lapse of two or three years. We 

 recommend it, for its beauty and fragrance, to all 

 those who love a fair flower in October. 



H&manthus Coceineus. There is a deep solemnity 

 M 



