장음표시 사용
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Terebintha vulgaris, Pinus sylvestris. The Common Turpentine. Terebinthinae oleum,
The Melis. S. N. G. 333 Tormentillae Radix, Tormentilla officinalis. Coimnon Tormentit Eost. S. F. B. 332.
We are uidebted to the French traveller here cited sorine di covery that the gum Tragacanth of commerce, is the produce of a species of Astragalus not besere known. It is described and figured in the fifth volume of Olivier's Traveis, under the name of Astragaltis mcrus, being different both Dom the A. Tragacantha of Linnaeus, and Dom the A. gum-misdra os Labili ardiere. It grows in the north of Persia.
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Veratrum albUm. The Loot. S. P. IV. iv. 89S. M. B. t. I Oo. Viola odorata. S. P. IV. i. II 65. M. B. t. 8 I. S. F. B. 2 S.
Spanish White Wine, called in Englisti,
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Aratum distillatum. P. L. I 78 I. P. L. 1715. P. L. 1720.
Vinegar is prepared in this country as an article os trade, hy a second fermentation of Wori or infusion os mali Whicli has previously undergone the spirituous fermen ration; and besides the solubie extraneous substances Whicli the vegetablematter itself supplies, others are commonly added by the manufacturer, such as sulphuric acid and colouring matter. The object of the present process is to separate these, andio obtain the acetic acid of an uniform and suffcient Strength. The use of glass vesseis is intended to do away the possibility of the solution os ei ther copper or lead, to the contact of whicli metals the acid is exposed is prepared in the ordinary Way; yet, notWithstanding this caution, it ill be Dund, stom i de convenience of iis application to the
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preparation os larger quantities, that the common copperstill with a pewter Wpum, is most frequently empto 'ed. In the distillation a greater heat is not to be applied than is sussicient to ke p the liquor moderates y bo ling, Whicli ithegitis to do at 2I2'; for is the heat be urged too far, orcontinuen too long, it gives to the distilled acid an empy- reumatic sineti and taste Whicli it ought uot to possess. Thefrst part whicli pa ses o ter on distillation is the water, stightly impregnated with ncid; and , in order that the more acid pari Whicli sub equently follows may be stronger, thefrst one- eighth is directed to be thrown away, 'Dd the neXtsi x-eighths Whicli pass form the Aoui id of t e Ph. macopoeia; the remaining one- ei gluti in the retori coma ins thesaline, colouring, and mi Cilaginous mae ters, aud the ulphuricacid; some acetic actu also rematris, in a more concentraled
state th in that Wioch has actuallu passed over; but uae greater heat wh in Would be require t for iis distillationwOuid decompose the vegetable matter With whicli it is combined, and thus produce a strong empyreumatic smelland flavour, lihe that acetic acid Whicli is actualty obtai neclin higher temperatures bu distillatiora os Wood or Other vegetable substances. Thus prepared it is considered to hesuffciently strong for ali medicat pui poses; and there reno second process is no given, as sormerly, for obtaininga stronger acid by the decomposition of any of those salts of whicli it fornis a pari; especialtv since it is ascertained, that there is no other disserence in the nature of the aciditself prepared in any of theso ways, than that one is in amore concentraled state than the other Dar G. An. Chivi. V. U. . Is the acid be propared correct ly, it Uilt be colourless, and of a graterat pungent peculiar acid taste. ones ut dounce ought to dissolve at least tela gratias of carbona fe
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Flores Benzoes, P. L. 17S7. Flores Bengo i, P. L. II20.
rahe of Bengotia, a potand and hal Fresti Lime, four OUII COS. Wnter, a gallon and lini f. Muriatio Acid, four fluido unces. Rub together the Bengoin and Lime, ilienhoil them in a gallon of the Wator for hais anta Our, Constantly Stiri ing, and when it is collipoui ossilie liquor. Boil What rem atris a secondtime in four pinis of Water, and potar ois theliquor as bes ore. Alix the liquors and holidown to half, then Stra in through Paper, and add the muriatio acid gradually untii it Ceases to Produce a Precipitate. Lastly, having potired off the liquor, dry the poWder in a gentie heat: put it into a Proper Vesset placed in a Sand bath, and by a very gentie sire sublime the Bengoic a id.
Benzian is a concrete balsam, consisting of a peculiar acidmixed with resin ; this acid is called Bengssic, and it is the object of the present process to separate it. Chemisis have effected this in various Ways, et ther by sublimation, Whichgives beauti fui foliated crystais, but requires to be repeated thrice, and pressed after eacti sublimation belween bibulous
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paper, to obtain them Wilite and Dee Dom any adherent essentiat Oil; this mas the process of the last Pharmacopoeia: or, by forming some of iis solubie compounci, and afterWarddecomposing them so as to precipitate the acid. or, by sim- ply boiling the Benzoin in water Whicli dissolves the acid, and as it coois allows it to separate again. ux . The tWo former processes are here combined; first the acid is separated according to Scheele's method, this consisis informing a benZoate of lime, and adding to the solutionthereos muriatic acid whicli precipitates the benetoic, while the neW compound muriate of lime remains dissolved; secondiy, this precipitate is subjected to one sublimation Whicligives iis usual foliated crystalline appearance. The Edin- burgh Pharmacopoeia forms a benZoate of soda, precipitates the acid by sulphuric acid, and afterWards crystalliges it bysolution in hol mater, Whicli dissolves a larger quantity than
coid. Benzoic acid has a strong, pungent, aromatic, Peculiarodour. Iis crystals are ductile, not pulverigable; it sublimes in a moderate heat, forming a wllite, irritating smolae. It is
solubie in about 24 times iis meight of boiling mater, Whichas it coois precipitates lis of What it had previolasty dissolved. It is solubie in alkohol. It may be crystalli et ed by solution in botling water, as by dissolving an ounce in a piratand a Jaalf of water, and afterwards allowing the solution tocool; or by sublimation , but as in iis crystalline form it is notreduci ble to poWder by mechanical means, it has been Some- times thought better sui ted to the purposes of medicine tokeep it in that more divided state in Whicli it is obtained by precipitation alone.
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CITRIC ACID. Talie of Lemon Juice, a Pint. Ρrepared Challi, an o an CO, Or nsmuch as may be sufficient tosaturate the Juice.
acti addition, and then potir oir the liquor. Vasti the Citrate of Lime Whichre mains by repented additions os fresti wator, and then dryit. Add the diluted sulphurio ac id to thedried po der, and Loit it for ten minutes, then press it strongly through a linen cloth, and uster variis iit ter it through paper. Letthe cloar liquor Whicli lias pa88Cd evaporate in a gentio heat, So that ciyStais may forna as it glis Colcl. To render these crystals pure, dissolve them a s 'conii and third time in Water, an dastor caeli solution 11 l ter the liquoi, boli itdo via, and Sot it by to crystallige.
The generat use of temon juice for the purposes of medicine, the uncertainty of obtaining it stoin the fresti fruit,
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and the dissiculty of keeping it unchanged, have rendered the
adoption of the present form expedient, is not absolutely n cessary; and there are also sonae politis of praetice, as in theexhibition os effervescing draughis, Where the diminished bulla of the acid in the sortia os crystals and iis sto ver actionas it dissolves Dona a solid state, give it considerable a luantage. This process oWes iis origin to Scheolo, and the acidhas thus been for some years prepared uPOn a large scaleand in a very pure state by Alr. Cox veli of Fleet-street. Itdeponds upon the formation of an insolubie citrate of lime, Whicli is astorwards decomposed by the stronger asini ty of sulphuric acid; and the delached citric acid rem alias dissoluod in the liquor, While the ne ly-formed insolubie sulphate oflime precipitates. The liquor Whicli contains the citric acidis evaporatcd untii the crystals form as it cools; but Domthe action of the sulphuric acid upon some adherent muciuaginous matter, the sirst crop of crystals Will be smali, of adarla brown colour, and impiare; their colouring matter canonly be separated by a repetition os the solution and crystalia ligation twice, an l, is the crystals be not then colouri ess and weli fornacd, even a third time. The use of rather more sulphuric acid than is requisite to the decomposition of the citrato is intended for the complete destruction of the mi cilage, sor Without this be effected the acid Will not crystallige. This dissiculty of crystalligation has been urged against the preparation altogether, and a concentraled liquor has bysome been suggested as more convenient; probably much of this objection will be removed by practice, for that an elegant and pure article may be prepared upon a large scale, the great supply Which Mr. Coxweli is enabled to malae sussiciently proves. of the crystalli Zed acid, one ounce dissolved in one pint of water is eques in strength to one sentos common te inon juice. Equat paris of the crystals and tubcarbonate os potass are sussicient for the mutuat satura -
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the admixture of iis essentiat Oil, and Whicti for Some pur- poses may be a useful addition. The crystals are rhomboidalprisms, Whose Sides incline to eacti other at angies of 12O
and 60', ternii nating at each end by Dur trapeZoidat faces whicli include the solid angies. They are not altered by expostare to air. Water at 2l2' dissolves tWice iis Weight, Is paris of cold water dissolve Ι00 paris. It would he advantageous is the citrate of limo could bemade and imported as weli as the fruit iiseis; for the greater perfection of the fruit in Carmer climates, the quantity ofacid they yield, and the smali comparative space whicli the saltilius prepared Nould occupy, Would ali tend to diministi iis present price very considerably. It may be and has been attempt-ed to substitute for it the cheaper tartarous acid, hut this may he detected is to a solution of the lalter a solution os tartrate os potasti be added, for an insolubie supertartrate os potasti mill then be formed and precipitate in granular crystals. This preparation properly made, OWes non e of iis acidity to adherent sulphuric acid; is it does, the precipitate yiel ded by asmali addition of solution os acetate os lead, Will, as sulphateos lead, be insolubie in acetic acid, while citrate os lead Willhe onti rely solubie in the fame menstruum. It may farther be observed, that although the process heregiven Will commonly ansWer, yet, that as temon juice some- times varies in the proportion of acid it contains, it may occasionalty require Some modification of the quantity of sulphuric acid to be added. Proust states Iurn. P s. 52. that paris of citrate of lime require 20 paris of sulphuricacid os a sp. gr. I, I 5 for this purpOse.