M I.AWSOXIA. 



contrivance of mat medical practitioner who wished to prescribe it 

 for U b*ont of nU acrofulou* patinta. [Aid*] 



aWSO'MU, a genus of Plants belonging to the natural order 

 IfOfmetf, which, consisting of only on* or two species, may be 

 (bund in most Oriental regions in garden* or in field cultivation. 

 The genus is characterised by having a 4 partite calyx, 4 unguiculate 

 petal*, 8 stamen*, s sessile ovary, the capsule scarcely dehiscent, or 

 rather forming a globular membranaceous 4 -celled berry, with several 

 angular reds in each orlL 



It is disputed smoog botanists whether this genus consists of oue 

 or of two species ; in the Utter case, one species being armed with 

 thorns, waa called L. tyinota, and the other being without any, was 

 named L. imirmu, by Linnaeus. De Csndolle has followed Lamarck 

 ia uniting them together under the name L. alba, stating that when 

 young the plant is unarmed, but when older become* thorny from 

 the hardening of the smaller branches. 



The natives of North India distinguished the unarmed species by 

 the name Phoolke, or flowering Mhendee, It U a much smaller plant, 

 but flowers most abundantly. The thorny species is called Mhendee ; 

 this, beside* being s larger plant, contains a greater proportion of 

 colouring matter, and is extensively cultivated in the vicinity of 

 Sidonra, near the north-west bank of the Jumna. The flowers of 

 both are corymbose, white, and powerfully fragrant ; the leaves smooth, 

 opposite, oval, lanceolate. To the latter species or variety the Arabic 

 name Hinna or Henna is more especially^ applied, which, in many of 

 their medical works, a* in that of Serapion, is described under that 

 of Al Kanna, where it is interesting to observe he quotes the 

 description by Dioseoride* of Kmtpot, ss applicable to this plant 

 This Kupros, or Cyprus, is moreover supposed to b* the Copher of 

 Scripture. ('Canticl.,' i. IS). Beside* the similarity of name, no 

 plant is more likely to have been alluded to in the above passage, as 

 no other is more highly esteemed or more frequently employed than 

 the Hinna, and it would appear to have been applied to the same 

 purposes from very remote antiquity. All oriental travellers describe 

 the us* of this plant by Asiatic women in dyeing their nails snd the 

 tips of their fingers, ss well ss the sole* of their feet, of an orange 

 hue with the leave* of the Hinna. It is also used by the men for 

 dyeing their beards, the orange colour being afterwards converted to 

 a deep black by the application of indigo. That this plant was 

 similarly used from very early times is highly probable from the 

 allusions to it by poets, ss well as from some of the Egyptian 

 mammies appearing a* if the nails had been similarly dyed. 



LA'ZULITB, LAPIS LA'ZULI, a Mineral which occurs crystalline 

 and massive. Primary form of the crystal a cube, but occurs in 

 imbsddsd rhnmhin dodecahedrons. Cleavage parallel to the planes of 

 the dodecahedron. Fracture uneven. Hardness 5'5 to 6'0. Colour azure 

 of bin*; *treak paler blue. Lustre vitreous, 

 Specific gravity 276 to 2*94. It intumesces 

 without fusing. It occurs at SaUberg and in 

 BtrrJs, also in the United States. 



Massive variety amorphous, sometime* in grains, imbedded. It 

 fuss* on charcoal, when pure, into s white glass. It is brought from 

 Penis snd China, and is employed in the manufacture of ultramarine. 

 The following are analyse* by Umelin and Fuchs : 



Fuch.. 



. 

 Alumina 



' i 



:. . 



i 



110 



16-0 



8-0 



4-0 



9-0 



Phosphoric Acid 

 Alumina . , 

 Magnesia. . 

 Silica . 



Protoxide of Iron 

 Water . 



41-81 

 8573 

 9-84 

 3-10 

 264 

 6-06 



H ' '.'7' - 



H SMM improbable that so different result* should b* obtained 

 from Iks same miners! Dr. Thomson admits the presence of phos- 

 phoric scid ; the analysis by Fuchs is therefore most probably the 



LEAD. The properties of this taste! are. that it bass bluish-gray 

 colour, and i* of considerable brilliancy when fresh .urfscessre formed 

 by catting i if H has not been cooled too rapidly, it is so soft, that 

 ev%n whsa pises* of oMU-idarsbU thiekns*. U may bs easily bent 



may be easily bet 



It soils slightly, sod leave* on paper or doth a mark after friction 

 isssniUiaf that of plumbago. Its specific gravity is 11-445, but when 

 impure not Krister than 11-861 Lead may b* rsduoed to thin 

 Ismiasr. bat its Vmscity is rttmn-lv slight; so that a wire about 

 on tsath of an boh to dfamster breaks with a weight of 80 Ibs. It 

 at about ir, snd when slowly cooled crystallise* in octane- 

 H u not a volstil* metal, for In close vessels It may be 

 I to whiteness without subliming. When exposed to the sir It 

 i oxygen and carbonic scid slowly, and acquire* s superficial 

 J erf carbonate of Issd. In dialled water which ha* been (reed 

 i aad kept from the contact of the sir, it undergoes no change ; 

 bat if ft b* exposed to air and water, H is oxidised sad converted into 

 i of ksd with soosidsrabU rapidity ; this carbonate has the 



. an few in number; indeed the 



LEAD. Mi 



only one which can properly be considered as a working or* is the 

 Sulphuret, but there are various combinations of lead occurring in 

 nature, of which we shall give a brief account. 



Native lead i* of very rare occurrence, and in some case* of very 

 questionable origin, ft has been found in small masse* in the lava 

 of Madeira, and also in the neighbourhood of Alston in Cumberland ; 

 it is in small globular masses, imbedded in galena, or sulphuret of 

 lead, and a slaggy substance, accompanied with blende and crystals 

 of quartz. 



J'rotariiU of Lead: ffatire Mauicot. This occur* in amorphous 

 msnsni Fracture earthy. Brittle. Specific gravity 8-0. Colour 

 yellow. Opaque. Externally dull, internally of a semi-metallic lustre. 



It melts readily by the blow-pipe, and, according to Dr. John, 

 it consist* of 



Protoxide of Lead . ... 87'882 



Carbonic Acid 8-846 



Lime and Oxide of Iron . . . 0*481 

 Silica (ferruginous) .... 2-404 



94-113 



Dtutoxide, or Setquioxide of Lead : Native Red Lead : Native 

 Minium. It occurs amorphous and pulverulent; colour carmine red. 

 Hardness 2*0 to 2*5. Specific gravity variously stated. Dull. By 

 the blow-pipe on charcoal it is reduced to the metallic state. It is 

 supposed to arise from the decomposition of sulphuret of lead and 

 the oxidation of the metal. It occurs in Yorkshire, Suabia, Siberia, 

 and some other places. When used in the arts red lead is artificially 

 prepared. 



Chloride of Lead: Cotunnia: Cotunnite. It occurs in small flat 

 colourless crystals in Cornwall, and at Vesuvius in acicular crystals of 

 an adamantine lustre inclining sometimes to pearly or silky. Specific 

 gravity of the chloride from Vesuvius 1 *897. 



It fuses by the blow-pipe, and is soluble in a large quantity of water, 

 and, according to Berzelius, consists of 



Chlorine 25*48 



Lead 74-52 



100 



Di-chloridt of Lead: Benelite. It occurs iu crystalline msnnnn, 

 with a fibrous and radiated structure, on earthy black ore of man- 

 ganese. Hardness 2*5 to 3*0. Specific gravity 7'0 to 7*1. It is found in 

 the Mendip Hills in Somersetshire. According to Berzelius it 

 consists of 



Lead ... ... 83-20 



Chlorine 

 Carbonic Acid 

 Lead . 

 Water . 



1877 

 1-03 

 1-46 

 0-54 



-100 



Sulphwct of Lead : Galena. This almost universally diffused ore 

 occurs in attached crystals and massive. Primary form the cube; 

 the cleavage easy, parallel to its faces. Fracture conchoids!. Hardness 

 2'5 to 27. Scratched by carbonate of lime. Colour lead-gray. Lustre 

 metallic. Opaque. Specific gravity 7*568. The massive varieties 

 are amorphous, the structure granular, and compact 



By nitric acid it is converted into white insoluble sulphate of lead. 

 By the blow-pipe on charcoal the sulphur is first dissipated, and then 

 metallic lead is obtained. 



In Cornwall and Scotland the veins of this ore traverse primary 

 rocks. In Derbyshire it occurs in veins or beds in transition rocks. 

 It very commonly contains a considerable portion of silver, and is often 

 mixed with small quantities of some other metals. Galena is very 

 commonly associated with calcareous spar and fluor spar, blende, 

 calamine, carbonate and sulphate of barytea, and in Greenland with 

 cryolite and spathose iron. 



The deposiU of this ore are remarkable for their extent in the 

 United States. They abound in what is called the ' cliff limestone ' of 

 the state* of Missouri, Illinois, Iowa, and Wisconsin. The lead of com- 

 merce U obtained from this ore, and it is often worked for the silver it 

 contains. The following is its analysis by two eminent chemists : 



Dr. Thompson. Deudant. 



Lead . , 85-13 Lead ..... 79-6 



Sulphur .... 18-02 Sulphur .... 13'4 

 Iron .... 0-60 Silver . . . 4 . 7'0 



98-65 lOO'O 



S-sWvrsI of Ltad, or Clatutkalite, It occurs missive. Structure 

 granular, Colour lead-gray ; resemble* fine-grained sulphuret of lead, 

 but is softer, and rather more blue. Lustre metallic, but rather dull. 

 Opaque. Specific Rravity from 7'187 to 7'697. When heated in a 

 tub* selenium sublimes; by the blow-pipe on charcoal it bums 

 with a blue flame, and the peculiar odour of selenium. It occurs in 

 the liars. According to the analysis of Rose, it consists of: 



Selenium 25-69 



Lead 74-81 



99-40 



The above are the principal native binary compounds of lead. We 

 proceed to notice those which are composed of an acid and oxide of 



