LIME. 



hefe phenomena do not ceafs till it has ahforbed one-lhird and clofed at one end, put fome pieces of phofphorus, fo u 



to lie at the clofed end of the tubt. Lot the remainder of 

 the tube be filled with bits of newly burned quicL-lime, 

 about the fize »f large peas, and then Hop the end of the 

 tube with a chalk or dry clay Hopper, not lifting very tight. 

 Let the tube be now paffed through two holes of a port- 

 able furnace, the furnace being about lis inches in diameter. 

 One of the holes muft be a htlle below the other, lo as to 

 give the tube a fmali inclination to the horizon, the open 

 end being higheft. Let the middle part of the tube be 

 heated red-hot, and then draw gradually the end containing 

 the pholphorus into a heat fufiicient to fubhme the pbof. 

 phorus. The vapour of the latter will now pafs throucrli 

 the red-hot lime, a great portion of which will combine 

 with it, forming the phofphuret of hme. If t!ie vapour ef 

 the phofphorus come too rapidly it pailes by the loofe (lop- 

 per, but fo foon as the whole has been fublimed, let the 

 end be llopped more clofely ; and let the tube be witlidrawii, 

 keeping it well (lopped till it is perfectly cold. Tiie whole 

 of the contents of the tube may now be Ihaken out, and the 

 darkeft coloured pieces felefted, which mud be kept in a 

 well (topped dry bottle. 



The phofphuret of lime, thus prepared, is of a deep 

 brown colour. 



Wlien thrown into water it does not diflolve, but bub- 

 bles ot gas are feen to proceed from it, which coming ta 



of its weight : in this ftate it is called y/urit^a lime. 



Many other fubftances are capable of furniiliing lime in 

 a ftate of tolerable purity. Ot thefe are the ftaladtite of 

 Derbyfliire, chalk, white marble, and fome of the other 

 marbles. 



Lime is not fufed by the greateft heats hitherto pro- 

 duced, although it is fufceptible of fudon by very flight 

 admixture of fome earths and metalhc oxyds. 



The change which takes place in all thcfe bodies which 

 afford lime by burning, was not explained belore the dif- 

 covery of carbonic acid by Dr. Black. The pecuHar qua- 

 lities of quick-lime w^ere fuppoied by Boyle and by Newton 

 to arife from the fire fixed in it by the procefs of burning. 

 Others fuppofed its cauilicity to arife trom the prefei ce of 

 an acid formed by the heat. Dr. Black, ho^vever, demon- 

 ftratedthat the qualities of lime were njt to be atifibuted to 

 the prefence of any fubttance in lime, but to the a fence of 

 vater and carbonic acid, the latter of which he at the lame 

 time difcovered. 



If lime be added to vrater at 60°, it dilTolves about .ooj 

 of its weight. It appears from the experiments of Dalton, 

 that cold water diffolves more lime than hot ; a property not 

 common to other bodies. According to this ingenious 

 chemift, water at 60 ' diffolves ^i-^ of its weight ; at 130 , 

 ^i, part ; and at 312°, -^Vo P^t- 



The fohition of lime m water is commonly called lime- the furface burft, and inflame fpoiitaneoufly, producing a 



'Ujalir. When lime-water is expoled to the air, it foon beautiful ring of white fmoke. 



becomes covered with a pellicle, exhibiting the prifmatic Thele phenomena are occalioned by the prefence of a 



colours, which gradually thickens into a cruft, and by its fubftance called phofphuretted hydrogen gas, which has the 



weight falls to the bottom of the liquid. This has been lingular property of taking fire at the common temperature, 



called the cream of lime. It is produced by the lime com- The water is decompofed by the phofphuret. The hydro- 



bining with the carbonic acid of the acmofphere, by which gen combines with a portion of the pholphorus, forming 



it becomes infoluble, and is feparated from the water. the gas above-mentioned, while the oxygen of the fame 



The fame feparation takes place by breathing through 

 lime-warer, from the prefence of the carbonic acid afforded 

 by refpiration. 



Lime combines with feveral of the combuftible bodies, 

 forming peculiar compounds. When two parts of lime and 

 one of fulphur are heated together in a crucible, they unite 

 in forming a reddifh mafs, which is the fulphuret of lime. 

 When this compound is moiftened with water, the latter is 

 decompoled. One portion of the hydrogen of the water 

 unites with a portion of fulphur, and efcapes under the form 

 of fulphuretted hydrogen gas. Another portion combines 

 ■with a part of fulphur and lime, forming a triple compound 

 of fulphur, hydrogen, and hme, galled an hydroguretted 

 fulphuret of the earth, wliile the oxygen of the decompofed 

 water, with the remainder of the fulphur and lime, forms the 

 fulphat of lime. 



The hydroguretted fulphuret of lime is of a greenidi- 

 yellow colour. If expofed to the air for fome time, it 



gradually abforbs oxygen, and is converted into fulphat of and the colour dilappears. 



combines with the remainder of the phofphorus, forming 

 pholphoric acid, w'hich with the lime fcrms phofphat of 

 lime. Befides this, a portion of the gas firil combines with 

 the phofphuret, forming an hydroguretted phofphuret, which, 

 if taken from the water belore it is decompofed, and wiptd 

 dry, retains the gas. On pouring muriatic acid upon it the 

 gas is hberated, and inltantly inflanies. 



Lime does not combine with any other of the inflam- 

 mable bodies, but it combines with leveral of the metallic 

 oxyds. 



When any of the oxyds of lead are boiled with lime and 

 water, a portion of the oxyd is diffolveJ. The folution, on 

 evaporation, aifbrds imall cryllals. 



This compound has the property of ftaining wool, hair, 

 nails, horn, and fome other animal lubftances, of a deep and 

 agreeable brown, which by expofure to the air difappeari. 

 This colour appears to be the bro.vn oxyd of lead com- 

 bined with the fubilance. An acid initautly diffolves it. 



lime. It, however, it be kept in folution in water in a clofe 

 veffel, fome of the fulphur gradually precipitates, leaving in 

 folution the hydrofulphuret of lime. See Sulphuretted 

 Hydrogen-. 



The hydroguretted fulphuret of lime has the property of 

 difTolving charcoal as well as fome metals, and metallic 

 oxyds. 



Lime alio diffolves the red osyd of mercury, of the fo. 

 lution affording yellow cryllals. 



Lime has the property of combining with fome of the 

 other earths and metallic oxyds, forming mortars of different 

 qualities. Dr. Higgins, in his book upon cements, propoftd 

 the following as the bell compoiition for common mortar : 

 three parts of fine walhed fand, four parts of coarfcr fand. 



The hydrofulphuret of lime is formed by palling ful- one part of newly flacked lime made up with as little water 



Moitar, 

 1 



phuretted hydrogen gas through lime-water. This gas 

 unites with the lime, forming a compound of a difagreeable 

 bitter tafte. 



Phofphuret of Lime. — This fubftance may be formed as 

 follows; into an earthen tube about 12 inches long, or a of m.i king mortar, which is not known to the moderns, 

 glafs tube coated with equal parts of fand and pipe-clay, A great improveir.eut has lattly been made in making 



G 3 ocmeut* 



as poffible, which he recommends to be fott water 

 thus formed, becomes very hard m a little time, anU con 

 tinuesto become harder for a great length of time. Hence 

 has arifen the miftake, of the ancients being in fome fecret 



