1013
of this ^ ( Transl. of the Pharm.) gives the following explanation
ea]] ec i ?5. oc . ess ' “ The quina exists in combination with a peculiar acid,a cert ■ ln * c Acid, forming with it Kinate of Quina, which is soluble toe mplo ln e xtent in water, and is rendered more so by the sulphuric acidOlay jT e ‘l in the process, and perhaps by decomposing it. Whateverkini c 6 -^ le shde of combination, the solution contains sulphuric acid,latter aiu l quina, mixed with extractive and colouring matter, thethe s r ng °i by die animal charcoal. On adding oxide of lead
ins ol, i!’ Ulric a< 'i ( l combines with it, and the resulting sulphate beingtio n . j i s precipitated, while the kinic acid and quina remain in solu-l^d' n' 1011 am nionia is added, after the separation of the sulphate ofkinic acid unites with it, and the kinate of ammonia formed ishi tle( j e ’ while the quina is precipitated, and this, when afterwards com-iv,... „ "' u h sulphuric acid, forms disulphate of quina, which crystal-
'•Zes.”
The
ph ate e directions of the Edinburgh College for the preparation of disul-°f quina are as follows:—
ovv Bark, in coarse powder, one pound ; Carbonate of Soda, eight ounces;
K& fYe . llu
jhffc C half a fluid ounce ; Purified Animal Charcoal, two drachms. Boil the• "Ived 8 .* 1 ”° u . r * n l° ur P> ,lts of water, in which half the carbonate of soda has beeu."'Uli yy f ’ str ain and express strongly through linen or calico ; moisten the residuuml0 Ur w :., r > and express again, and repeat this twice. Boil the residuum for half an' • . our pints of water and half the sulphuric acid; strain, express strongly,!!!'!»foimk Wate r, and express again. Boil the residuum with three pints of waterWith ti, e rtl part of the acid; strain and squeeze as before. Boil again the residuumr ' v ho| S;in ' e f l ua utity of water and acid ; strain and squeeze as formerly'. Concentrate'e re ma^ T'd lifinids to about a pint; let the product cool; filter it, and dissolve in it• *firhtl v Inaer °f the carbonate of soda. Collect the impure quina on a cloth, wash ita pj^ , a "d squeeze out the liquor with the hand. Break down the moist precipitate$ 2 ®; 'd distilled water; add nearly one fluidscruple of sulphuric acid, heat it toShould any precipitate retain its gray colour, and thedrop by drop, stirring constantly, till the gray
-and
water:
Co]
fluid b'l U Stlr occasionally,f Ur di. ,leu ^ ra l’ “dd sulphuric acid, til s °da Sa PP ears * Should the liquid redden litmus, neutralize it with a little carbonateLa -, 10u ^ crystals form on the surface, add boiling- distilled water to dissolve
through miner. nrto
. ... 6tot ,„J
cry st ,„.' digest the solution for fiftein minute exceeding 140°.
l| >e m e ,L S U , cfore - Dv >' \ lie y V qi yield a little more salt by concentra-
uiother-liquors of each crystallization will y
don«i:.. 1
U0),
and
coolin
Tl
he
c arh 0 ~ °bject of this process is to extract, by means of the solution ofgUu, o le °f soda, the acids, the colouring and extractive matters, the• from the bark, but leaving the cinchona alkaloids. Stoltze usedJ’he all * v'T 080 hme, Badollier and Scliarlau caustic potash (see p. 999).hi \ Va . ilane decoction has a very deep colour. Bv boiling the residuumHie a ,j (P ac idulated with sulphuric acid, the alkaloids are dissolved. Onhie i rr . ^ lon °f carbonate of soda, double decomposition takes place, andUci ( |u]' l,r f hoinia is precipitated. This is afterwards dissolved in waterQ]]] Ze c y with sulphuric acid, and the filtered liquid set aside to ervs-boi][ ‘ The impure disulphate of quinia thus obtained is re-dissolved in"ith ai ■" a *' or > hiul the solution, after being decolorized by digestion1 ha Unal c barcoal, is filtered, and put aside to crystallize.
P* e use 0 repeated this process, which has the great merit of obviatingboth si a ^ c °bol, and I believe it to be an excellent one, combininghpbeity and economy. In one experiment l employed one lb. of