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Natron tartarigatum, P. L. 1 87.
I ake of Sub carbonate of Soda, t venty
This sali consists of tartaric acid, soda and potasti, thesoda only combining With the superabundant acid of the super sest: it is there re a triple sali, and it has been judged more conVenient to express this difference by the adjective tartarizata, than to introduce the three Words necessary to iis description. Iis crystals are prisms of eight or ten unequalsides, having their en is truncated at right angies. It is solubie
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Itho tartrate of potasti, iis taste is bitter, and ii essioresceson eXposure to air. Vauquelin states, that it consists of tartrate of potc. h 56, tartrate of soda 46. It has been called sali of Seignette Dom iis inventor, and also Sal Rupellensis, or Rochelle saltis No distinction was made, P. L. 1745, betWeen the salis prepared by adding soda or potasti to the super sali, and both mere hept indiscriminately under the name of solubie tartar. Iti this, as in the sulphate os potasti and many other Salis, aestit excess of aikali disposes the crystals to form more readi ly and to render them more perfeci in their sorm.
iron intriolatum, P. L. II87. Sal catharticus Glauberi, P. L. I 45.
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This preparation depends upon the Same principies asthose upon Whicli the sulphate os potasti is formed; but soda differs froni. potasti in iis relation to sulphuric acid, and does not strictly unite Witti it into a super sali; as,however, more than half their weight of water enter into the composition of the crystals of sulphate of soda, is that waterbe acid it Nili induence the character of the sali, and lienceiis saturation is as necessary here as in the former instanc
Iis crystals are fix-sided pristias terminated by two-sided pD rami is, but they are most commonly irregular and channelleaon thela fides. One part is solubie in sonaeWhat less than three of water at 6O', and in less than iis own bulla at 212'. Κirwan gives iis proportions as acid 23,52, pot-aSh I8,1 8,water 58. Is heated, it melis froin the agency of itSwater of crystalligation, and when this is evaporaled, it masbe fused by an increase of the heat. Aster this toss of Water, Kir an states it to consist os acid 56, potasti 44. In France ithas been prepared, by disturbing iis more regular crystalligationby stirring ; when it takes a silky spicular forna, and has bestia called improperly Sal d'Epsom. It will be observed, thalbesides this process sor iis formation, sulphate Us a Stantis aSan article in the catalogue of Materia Medica. The quantityobtained, accor ling to the pharmaceutic process, is not SULficient for the consumption; and theresere it has been judgedright to admit it also frona the manufacturers, Who PrePare large quantities of it, especialty in the works for muriate Ofammonia, Wherc, having obtained a very impure carbonate of
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amnonia in their first distillation os bones, they separate these by sulphuric acid, and afterWards employ a doubie de- composition by mixing sulphate os ammonia with muriate offoda; they sublime the muriate os ammonia and have thesulphate of soda lese, which, is it be crystalliged, is sufficiently pure and very cheap.
Natron praeparatum, P. L. I 78 .
Tahe of impure Soda poWdered, a POUnd. Boiling distilled Water, a gallon. Boii the soda in the water sor half an hour, and stra in the solution ; let the solution evn-porate to tWo pinis, and be set by, that Crystals may forna. Thro v a Way the rem aining
All barilla or heip contains much heterogeneoUS matteriand the Spanish, Whicli is the purest, is to be preferred. Ιt is prepared by the incineration os marine planis of various foris, and is found native in some paris of Africa. Water disvives the subcarbonates and Other salis, of Whicli, contrary to Whathappens with the subcarbonate os potasti, the subcarbonate of
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soda crystalliges frsi aster due evaporation; the firat cropyielded wili, theresere, be suffciently pure, and of theirregular form: in the second crop, the crystals Will contain a larger proportion of the other most predominant sali, the sulphate of soda, and approximate to iis form os crystal; onlythe sirit, therefore, is ora this account directed to be kept semuse, and the residuary or mollier liquors to be thrownaway. Iis crystals are formed of two laur-sided pyramidsapplied base to base, With the tops truncaled, forming a ten-sided crystal, but perfect crystali are not to be expected in preparations of any sali Upon a large scale, and the disposition whicli iis an es silo to the assumption of this formis sussicient. One part is solubie in imo of cold water, and in one of water at 212'. It emoresces on exposure to a dryair. The crystals consist os carbonic acid Il,4 2, soda 21, 58. ater 6Φ,OO, according to M an.
Apply a gentie heat to the soda in a Cleantron vesset untii it hecomes perfectly dry, and
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The crystals of subcarbonate of soda, is exposed to ala, losea part of their water, and emoresce or nil into powder. Ηence, the proportion os soda contained in the sali hept in the shops becomes indefinito. In this emoresced sali the proportion of water lost will be nearly one-hais of the whole. Byu definite exposure to heat the whole water maybe eVaporaled, and the sali thus prepared is more useful and uniform in many of iis applications. Care must be talaen that the heat be noturged too far, for a red heat deprives it also of iis carbonic acid. Dried subcarbonate. of soda contains, according to ΚirWan, carbonic acid 40,ol, soda 59,86; and IOO paris of the crystalsarct deprived of their 66 of water.
CARBONATE OF SODA. Tahe of Sub carbona te of Soda, a POUnd. Sub carbona te of Ammonia, three
Ηaving previora sty dissolved the soda in the water, adit the ammonia, thera by means of a sand bath apply a heat of 18o' for threelio urs, Or untii the ammonia be dri ven offLastly, Set the Solution by to crystallige. Therem aining Solution may be o vaporated an d
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This sali bears to iis subcarbonate the fame relation that carbonate os potasti does to iis subcarbonate; it is prepared in the fame Way, possesses the Same comparative advantages. and contains double the quantity of carbonic acid. Κla roth gives as iis proportions, acid 39, base 38, Water 23.
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The crystals of alum contain os mater, and when it Iuexposed to heat it melis and the Water evaporates aWay; thisis the object of the present preparation, Whicli is intended foreXternal use, and it should be remembered in preparing st, that a violent heri Will decomposo the sali and drive off the greater part of the acid also.
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Aqua aluminis composita, P. L. II8I. Aqua aluminosa bateana, P. L. 1745.
Tahe of Alum, Sulphate of Zinc, of each hais an
Dissolve at the fame time the alum and sulphate os ginc in the water, and then stratu the solution through paper.
LIME. lx, P. L. 1787, P. L. I 765. Calx viva, P. L. 172O.
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In the former Pharmacopoeia lime Nas ranked among the articles of Materia Medica, and talaeti as prepared for iis coarser uses in the aris: sor many purposes this would besussicient, but for others it is osten important that it si uid bemuch purer ; the present directions are theresere introduced. TWo fources also are tinen Dom Whicti it may be prepared; lime-stone and shelis of oysters: the latior of whicli containsthe least foretgn admixture: but even the former Wili beniuch purer than that Which is usualty prepared froni chath. om Whatever combination it be obtained, lime is always the Same Substance, possessing the fame characters, and producing the fame effecis, though it may differ in the proportion ofheterogeneous matters with Whicti it is mixed; the distin tions theresere Whicli mere formerly made belWeen iis medicat qualities as obtained from different fources Were Supe fluous, and Will not, in the present state os science, be lihelyto he xeneWed by the present introduction of more than one. It is necessary to the perseetion of the lime that the carbonic