ITM. 



CALcn.rs. 



M 



may |um, and thus form a guarantee against the f 

 a solution of that metal. [WATER.] 



Carbonate of lime may be artificially procured by sereral process us 

 as by pssaing carbonic acid gas into lime water, or by adding an alkaline 

 carbonate to a solution of any salt of lime in water. The precipitate is 

 at first bulky, but in a short time settles so as to occupy com|iarativerj 

 little space. Carbonate of lime is insoluble in water, and decompose* 

 by most aoids with the evolution of carbonic acid gas. It in in various 

 forms largely employed, as in lime-burning, glass mi If ing, the reductioi 

 of iron. Ac. 



.sW/UvnV arid and lime form sulphate of lime (CaO, SO,), frequently 

 called gypsum, selenite, and plaster of Paris, on account of its being 

 found in the neighbourhood of that city. It occurs largely in the 

 mineral kingdom. 



Sulphate of lime may be prepared artificially by several processes, as 

 by mixing a solution of chloride of calcium or of nitrate of lime with 

 one of sulphate of soda, or with dilute sulphuric acid. A bulky colour- 

 less precipitate U obtained when the solutions are moderately strong 

 which is sulphate of lime. This salt is nearly tasteless ; it requires 

 nearly 462 times its weight of boiling water for solution, and it is 

 nearly as soluble in cold water. It is insoluble in alcohol. It is met 

 with in most river anil especially in spring waters, and, as before indi- 

 cated, is one of the salts which imparts to them the property called 

 hardness. The air has no effect upon it ; the artificial as well as the 

 natural crystals contain water, and the salt is composed of 

 1 Equivalent of sulphugc acid = 40 



1 lime . . = 28 



2 water . . = 18 



Equivalent = 86 

 When heated, the water is expelled, but it has a great disposition to 

 regain this water, and when it is made into a paste with water it 

 becomes warm, and then a solid uniform mass in a few minutes. It is 

 upon this property of losing water by heat and recombining with it by 

 admixture with a small quantity that its use in taking casts, &c., 

 depends. When sulphate of lime is exposed to a violent heat it melts, 

 and yields an opaque vitreous globule. Sulphate of lime is not only 

 used for taking casts, but occasionally as manure, or rather, probably, 

 as a corrective of certain soils. 



Stlpkite { lime (CaO, SO, + 2 Aq.). Hydrate of lime absorbs sul 

 phurous acid with facility ; the compound forms a convenient source 

 of sulphurous acid. 



Usalir arid and lime form oxalate of lime (CaO, C,0 S ). This salt 

 exists in the form of calculi, and also in certain plants. It is 

 procured by adding either oxalic acid, or, which is better, oxalate of 

 ammonia, to a solution of a salt of lime. It is a white, extremely 

 insoluble substance ; it is dissolved by acids, except acetic acid, and 

 decomposed at a high temperature, and converted first into carbonate 

 and afterwards into pure lime. Oxalic acid and lime form so insoluble 

 a compound, that they are used as test* of each other's presence. 



Phmjihorir arid and lime form several compounds, one of which 

 occurs in nature. [APATITE.] 



There are some other phosphates of lime ; the ordinary triphosphate 

 U prepared by adding a solution of phosphate of soda to one of chloride 

 of calcium. A white powder, insoluble in water, but dissolved by 

 acids, is precipitated. It is composed of 



1 Equivalent of phosphoric acid = 72 

 3 lime . . = 84 



Equivalent = 156 

 or (SCaO, POJ. [BONK EARTH.] 



Three-fourths phosphate is obtained by mixing a solution of phos- 

 phate of lime in phosphoric acid with alcohol. It is a white substance, 

 which reddens litmus |nper on account of the excess of acid ; this 

 excess is removed by water, and then the neutral phosphate remains. 

 It i* composed of 



3 Equivalent* of phosphoric acid = 216 



4 lime . . = 112 



Equivalent = 828 



/>>*<" / !!, (iCaO, HO, 1'0 S + 4 Aq.) occurs in irregular six- 



Wil*. It u soluble in solution of rartioiiic acid, and in this state 



is not unfmiuriitly f,,,, n d in mineral waters. After heating to redness 



' 



1 Equivalent of phosphoric acid = 72 

 lime . . = 66 



Equivalent = 128 



fuftrpkatj^al' "/Inn' i- the name given to a mixture of crushed 

 burnt bones, oil of vitriol, and water, allowed to stand for a few ii 

 Mixed with earth, 



No- I. No. }. 



Burnt U.nwi . . . 2 part* 155 



Sulphuric arid . . . 1 100 to 150 



Water .... 8 WO 

 No. 2 is more soluble than Xo. 1. 



l%lane and lime act upon each other in a peculiar manner, whi.-h !< 

 not as yet perfectly understood. When hydrate >! lime i exposed to 

 the gas, it absorbs nearly one-third of its weight, and the r. 

 p..und lias been called a chloride and a hypochlorite ..f lime. A: 

 it* exact nature has not been 1. it is a most im|)ortant com- 



]Miuinl, and is used to a great extent for (lie purjtofwsof bleochin- 

 frequently called bleaching jtotcder. In solution it i employed as a 

 disinfectant. 



The ]>ro)>ertie8 of lime-salts are the following : They are colourless if 

 the acid contained in them is colourless. They have a lower - 

 gravity than baryta or strontia salts ; in other respect* they much 

 resemble the salts of these bases. Their solutions yield no precipitates 

 with Mil|ilmretted hydrogen, sulphide of ammonium, or a dilui 

 tion of a Milphate, Kiich as sulphate of lime.l.ut are precipitated I 

 bonateof ammonfal in the presence of chloride of ammonium. A soluble 

 oxalate (r//., oxalate of ammonia) is an exceedingly deli. 

 liim. precipitating that base from the most dilute solutions in tl 

 of a white solid, insoluble in acetic acid, but soluble in hydrochloric or 

 nitric ,ic id. 



<Al.ru.. \TIMi MA< HINKS. | M !( ,s. -. CM , ri.vTixo.] 



CA'LCULUS is the general term for inorganic concretions of 

 various kinds, formed in various part* of the liody, and bearing a 

 general resemblance in shape or composition to stones. The p:u 

 of which they are composed are frequently arranged by p. 

 chemical affinities into regular forms ; and in these, as in other ci 

 the process may begin around a fragment of some other Mil- 

 such as a clot of blood, a peUet of mucus, or some foreign KH|\ 

 loose in the fluid which holds the elements of the calculus in Dilution. 

 They are also formed by the mechanical aggregation about a in: 

 or otherwise, of particles of different kinds accidentally thrown 

 ther, and cemented into a mass by glutinous animal matter : or. 

 they may be the product of secretion: the more tlui.l 

 secreted matter being conveyed away or absorbed, while the sediment 

 gradually thickens and hardens into consistence, adhering peili 

 some rough surface or projecting point, or being deposited in a hollou 



where the accumulation is least liable to be displaced by fricti 



washed away by the fresh influx of fluid. 



Tartar of the Teeth. The most familiar instance of the last-men- 

 tioned kind of concretion is that which is deposited from the soli'. 

 mucus of the mouth between the teeth, and upon their outer surface 

 next the cheek. This affection is not only productive of deformity, 

 but of considerable injury to the teeth, which become loosened i 

 displacement and absorption of the gums under the increasing 

 sure of the moss. It may easily be prevented by a little attention 

 in the use of the brush, or remedied by the operation of miliini. 

 which gives no -pain, and should never be postponed when it ic . 

 sary. The substance deposited is gritty, of a dirty yellow colour, an.l 

 goes by the name of tm-lur, though it has no eoiiniiti.ui with the 

 vegetable product so called. It is stated to consist of the ph. 

 and carbonate of lime, 



fiillniry ( '!/< /('.. - Similar deposites, consisting nearly of the same 

 materials, occur under the tongue or in the substance of the cheek 

 in the ducts which convey the secretion of the salivary gland - int.. il,. 

 mouth. Tlu-y -..mctimcs attain a considerable size, and require on 

 incision for their removal. 



Pulmaiiar;/ Cunrrcltont. Hard irregular masses of phosphate of lime, 

 rarely larger than an almond, are frequently met with in the h.i 

 con.-umptive ]tttients. They are sometimes found imbedded in the 

 pulmonary tissue, to which they adhere intimately; but 

 quently in the middle of tubercular deposits, especially when these 

 take place in the substance of the bronchial glands. They occa- 

 sionally tind their way by ulccmtion into the air-tubes, and are brought 

 up by coughing. 



i ;i/,;iri mi* < 'iinrnti'HiK iii tin Hl,,'nl-reutU and Heart. Brittle earthy 

 de|xisits, consisting chiefly of the phosphate, of lime, are exceedingly 

 common, especially in advanced life, in the arteries, and in the valves 

 of the left side of the heart, the e.-ivities of which contain arterial 

 ihxxl. They are formed at first in nodules or scales, behind the 

 membrane which lines these jiarts Internally, and sometimes ae.-umu 



in extent as to convert the arteries into rigid 



o inqiede or even .-top the motions of the heart. They arc frequcnlh 

 he cause of atteiiritm and other serious diseases, particularly a kind of 

 mortification of the extremities called *. . .<, and th.v 



.reusing complaint, tniyniu /,/, irit, which is often found to arie from 

 rigidity of the arteries which supply the heart itself with blood. 

 These concretions are not, however, so often productive of mi 

 as might be expected ; for scarcely an individual passes the middle 

 KM-i.l of life in whom this ossification of the arteries, as it is termed, 

 Iocs not exist in a greater or less degrrc. The veins aie likewise sub- 

 eet. but much lew frequently, to ."inall corpuscular concretions called 

 ilil<lnJ!thrt (from #Atif., a vein, anil Aftfos, a stone). They appear to be 

 "lined liehind the thin lining membrane, which, as they gro. 

 mslied forward into the calibre of the vessel, inclosing them in a kind 

 if capsule, and forming a narrow pedicle by which they remain :.d 

 icrent. After a time they become detached and movable. When 

 hey occur in the veins upon the surface of the body, they may bo 

 en loved if troublesome; but they are not in genera] of any con- 

 sequence, and are seldom larger than a very small pea. They are 



