ASBAY OF OINOHONA B B K , BY A. PETIT. SROLLIUB has shown that the whole of the alkaloids of oinchona bark may be obhined in solution by treating, say 40 gra,mmes of the powdered bask with 800 p s . of a mixture composed of Aloohol, 96percent. . . . . . . . . G’iparty, Ether, sp. gr. W724 . . . . . . . . 733 .. Ammonia . . . . . . . . . . 32 .. Comparative experiments have shown me that the bark must be in as fine powder &IS possible, and that, if the mistme be shaken every five minutea, the exhaustion is as complete after one hour, as it aill be after five or six horns if merely maoerated. The next step is to pour off 600 gms. of the liquid, corresponding t o three-fourths of the dkaloids contained in the bark, that is, representing 80 gms, of the latter.THE A,NAIiYBT.121 Now add to the ethereal liquid enough of EL solution containing: one-fourth of its weight of sulphurio acid, so tlut the aqueous layer which separates W be just acid. In generaI, about 20 mbic centimetre~ will be mflident. This aqueous layer oontains all the alkaloid of the ethereal liquid. The layer is separated by a suitable fume1 (in fact the ethereal liquid s h d d be in a separating €unnel when treated with the atid), and the ethereal liquid again agitated with 5 C.C. of the diluted acid and 15 0.c. of water. This portion irS Hcewise septed, and added to the former. Now heat the aqueous liquid on a water-bath in order to get rid of the dissolved ether, then dilute it with two volumes of water, and precipitate with cawtio soda in excess. On stirring with a glass rod, the alkaloids coalesce together in a mass.The same result may also be obtained by warming the Iiquid on the water-bath. Transfer the alkaloids to a tared capsule and dry them at a temperature of 100" 0. I[f the l i q ~ d is not perfectly dear, it is passed through a tared filter, and the gain in weight of the latter when dried at 100' 0. added to the alkaloids in the capsule. We have now tibe weight of the total alkaloids contained in the 80 gm. of bmk, and from this we may calculate the quantity containedin one kilogramme. The next step is to ascertain the proportion of alJraloids soluble in ether. Proceed as follows:- Dissolve the total alkaloids in a slight exceas of dphurio acid. Add 25 C.C. of ether (sp. gr. O*fi24) and 6 C.C. of mmonia, and shake. The &doids soluble in ether are thereby taken up.Decant the ether: shake again with 10 C.C. of ether and decant again. Unite the ethereal solutions, let abnd 15 minute#, so thatthe alkaloids which are but little soluble in this menstruum may deposit; decant again, and shake the clear, decanted ethereal liquid with 10 O.C. of diluted dphmiio acid(1 in 20). Sepaxate the aqueoucr liquid ; agitate the ethereal solution with 5 O.C. more of the dihate mid, and add the second aqueous layer to the &t. Dilute the united Hquids with water to 25 c.o., heat to boiling, and saturate with pure diluted ammonia (I in 6). As soon as the reaction is faintly alkaline, the heating is interrupted. (212" F.). The sulphate of quinine w i l l now sepazate in h e needle-shaped cryst&. when comp1el;OLy cold, collect it upon a tared filter, and wash it with a cold saturated solution of sulphate of quinine ; finally dry it at 1000 C. (212' F.), ulltil the weight remains constant.We now have the weight of sulphate of quinine obhinable Prom 30 p. of bark, and, therefore, by a Simplo caIcuIation, that contained in one kilogramme. In order to prove that the dphate of quinine thus obtsined is pme, the d t is dissolved with the aid of sulphuric acid, and extmked by the polariso~pe. J3 the rotary power does not approach sufficiently dose to -288.8, with sodium light, at a temperature of 15" a., the salt must be purified by tz renewed trestment with ether and ammonia and reoryatallization.128 TPB% ANALYST. According 20 my expopionce, the polarhetrio deviation is proportional to the qwtity of salt dissolved; the amount of sulphuric acid does not influence this devia- tion, provided it is present in at least sufEicient quantity to form bisulphate of quinine. In practice, I prefer a solution mntRining one gm. of 'basic sdphate dried at 100" 0., dissolved in two m., of one-tenth per cent. sulphuric acid, and enough distilled water to make twenty C.C. Under these conditions the polariscope deviation is to -110" (for pure sulpbte of quinine at 15" 0.). Accurding to my experiments, it is necessary to add to the observed degree about one degree for every four degrees of temperature above 15' 0. These Werent treatments by acid, and the sepazations of the ether, are very rapidly performed if tihe operator has had some previous practice in these mmipulcations. A few hours me sufEcient to make IL complete assay of cinchona by this process.- .@6&&6 d6 .&ZIWMcde.