LIME. 



cements by combining lime with oxyd of iron and manganefe. 

 An iron ore aboundinij with clay , a calcareous matter, and 

 pyrites, have been introduced under the name of " Parker's 

 cement,'" from the name of the inventor and patentee. 

 After burning and grinding to powder, it has the pro- 

 perty of fetting rapidly when mixed witli water, and even 

 under water. This rapid induration can be explained, only 

 by fuppofing a great afTmity to exill between the different 

 earths and mctalUc oxyds in its compofition. 



Lime had long been fufpcfled to be a compound body ; 

 but it is only lately that this facl has been verified by ex- 

 periment. From the general refemblance of the earths to 

 the oxyds of many of tiie metals, Lavoilier fuppofed tlicm 

 to be oxyds of metals, which had fo great an affinity for 

 oxygen as not to be reduced by ordinary means. Several 

 imfuccefsful attempts were made to realize this conjecture 

 by different philofophcrs. 



In the late experiments of Mr. Davy, in which he dif- 

 covered the fixed alkalies to confid of metallic bafes united 

 to oxygen, this pliilolopher was led to iuppofe that the 

 earths, at leaft thofe having alkaline qualities, might be 

 compounds of peculiar bafes united to oxygen ; and in this 

 conjetbire he fcems not to have been mifled. 



Mr. Davy did not fucceed in obtaining the mctaloid of 

 lime in a pure Hate, as in the inllanccs of potafh and foda. 

 He fufed a portion of lime and potafli together, and ex- 

 pofed tliis compound to the action pf ilic Galvanic battery, 

 in the fame way he had done potafli and foda. He ob- 

 tained by this means a metallic fubllance, which dillered 

 from the metal ef potafh in being Icfs fuliliie, and took fire 

 as foon as it was formed. He fuccecded better by nioif- 

 ■ tening the lime, and mixing it vvilii red oxyd of mercury. 

 Thefe were placed upon a plate of platina, connected with 

 the pofitive end of the battery. A cavity being made in 

 the mixed mafs, a globule of mercury, weighing about 

 60 grains, was placed in it, and a connection formed be- 

 tween the mercury and the other end oi the battery by 

 means of a platina wire. By this means, the lime under- 

 went decompofition ; its metallic bafe combining with the 

 mercury. This amalgam was then diftilled in a glafs tube, 

 filled with the vapour of naphtha ; by which the mercury, 

 to a certain extent, was expelled, leaving a while mafs of a 

 metallic appearance, and of the colour of filvcr. This fub- 

 ilance, which no doubt was tlie bafis of lime, had fo great 

 an attraition for oxygen, that Mr. Davy could not fueceed 

 in examining its properties before it was burned and re- 

 converted into lime. He has given it the name of Cal- 

 tliim. 



Salts of lAme. — Lime combine.^ with the different acids, 

 forming peculiar compounds called falts. 



It pofTcfTes a ftrongcr attraction for the acids than aid- 

 mine, magnefia, or any of the metallic oxyds : hence the 

 exiftencc of aluminous, magncfian, and metallic falts arc 

 incompatible with lime. Several of the falts ot lime are 

 found native in great abundance, partieidarly the carbonat 

 and fulphat. We rarely find a mineral water free from fomc 

 of the falts of lime. They are molUy, however, the car- 

 bonat, fulphat, and muriat ; the reft of the native falts 

 being infoluble in water. 



Sulphat of Lim:. — This fait may be formed by difTulving 

 lime in the muriatic or nitric acid, and adding fulphiirie 

 acid to the clear folution, till the precipitation ceafes. The 

 fubftance which falls to the bottom is the fidphat of lime, 

 in a ftate of white powder. It abounds fo plentifully in 

 nature, that it is never manufaftured for fale. The native 

 rrvllals are right-angled prifms, with rhomboidal bafes. 

 Jt is alfo found fomeiimes ia cryilals of the form of four 



and fix-fided prifms, which are generally very tranfparent- 

 In fornc fpecimens thefe cryflals are very fmall, giving the 

 mafs a fibrous appearance. It occurs in Derbyfliire, in 

 large fenntranfparent maffes, modly abounding with yel- 

 lowifh-broun iireaks, occafioned by the prefrnce of iron. 

 Great quantities of this laft is worked into ornaments, and 

 ufed alfo i[i fculpture. 



This fait is foluble in 460 parts of water.at 60''. 



It is not altered by expolure to the air, at the common 

 temperature : if, however, it be heated to ignition, it lotes 

 its water of cryllallization, and falls into a fine wliite powder. 

 This powder, if left in the air, would re-abforb the water, 

 and aflume its chemical qualities. Wlieii this powder, newly 

 calcined, is mixed with water to the confidence of pulp, it 

 foon begins to lliftcn, becomes warm, and in a little tima 

 becomes very hard. During this Ihite it expands with great 

 force, fo*as to break very ilrong vell'els. It admits of 

 the nioR delicate calls being taken by means of it. The 

 fudden expanhon, at the time it is lofiiig its liquid f<ii;m, . 

 forces it into the moll minute cavities. It is employed b/' 

 artifls for makings cafls of bufls, and different ornaments. 

 The fame properties render it of great value to the manu- 

 facturers of pottery and porcelain. It is ufed in fome 

 countries for making the floors of upper rooms, as a fub- 

 flitutc for wood. In the laying of thefe floors, iome idea, 

 may be given of its expanlive force when fetting. Thin, 

 flips of wood, of a thicknefs equal to the expaufion of the 

 floor, arc placed between the wall and the pulpy mafs, till 

 tiie time it begins to afTume the folid form. Thefe flips are 

 then inllantly removed, to make room for" the expanfion. 

 If this precaution were not taken, fo great would be the 

 force, as to pulh out the wall in that part. 



Sulphat of lime is compofed, according to Bergman, of 

 46 acid, 52 bafe, and 22 water, in the 100. Kirwan'5 

 analyfis gives 59 acid and 41 bafe in the 100. Wenzc! 

 makes it 59-1^4 acid and 40.16 baft. 



Dalton makes the atom of lime 24, and fulphuric acid 



13 +3 X 7 = 34: lience, 



24 + 34 



100 



, which gives 



34 5**-^ 



58.6 acid, and 41.4 bafe, =: 100. 



This fait is faid to be ufed in America as a manure with: 

 much fucccfs ; but has not^been ufed in this country. 



Sulphllc of Lime This fait may be formed by adding 



fulphurous acid to the nitrat or muriat of lime. A white 

 powder is precipitated, which is fulphite of lime. This fait , 

 is fiduble in lOO parts of water. It. is flightlv efflorefcent 

 in the air, and ultimately is converted into fulphat. Wlieii 

 heated, fome fulphur is fublimed, and it affumes the ftate 

 of fulphat. This fait is compofed of 48 acid, 47 lime, and 

 J water, = loOi It has not been applied to any ufe. 



Nhrat of I, me. — The nitrat of lime may be formed by 

 adding powdered carbonat of lime to nitric acid, till the 

 efl'ervefcenct? ceafes. When the folution is evaporated to 

 the confiltence of fyrup, and placed in a very cold fitua- 

 tion, fmall needle-fhaped cryftals, after fome time, will ap- 

 pear : the fhape of thefe is fix-hded prifms. This fait is 

 cryflaUizable, but with difficulty, owing to its great folu- 

 bihty ; or, in other words, to its graat affinity for water ; 

 and when the cryftals are forn-sed, they fooii attract moillure 

 from the ai-, and difappear. 



When the folution is evaporated to drynefs, and the heat 

 contiinicd a fhort time, the mafs actiuires the property of 

 (liining in the dark. This fait is known by the name of 

 Baldwin's phofphorus. 



When a ftronger heat is applied, up to ignition, the fait 

 ie dccompofcd ; the acid is reiolved into nitrous gas, oxy- 

 gen. 



