32 



IJICTKINAKY OF THE ACTIVE PKINCIPLES OF PLANTS. 



Precipitated by sodium hydrate, amorphous becoming crystalline. 

 Chlorine water, etc. (thalleioquin reaction), as quinine. 

 Potassium permanganate, only slowly decolorized. 



(3) CINCHONINE A., C,,,H.„N.jO (Laurent, etc.). Crystallizes in needles 

 or prisms (no crystalline hydrate). Dextro-rotatory ; [a]R = 237'5 in 

 alcoholic solution. Melting point has been variously given as 140^ 165°, 

 2'i(t" by different observers ; pur|>le fumes are obtained on beating ; 

 reaction alkaline, taste bitter, non-fluorescent. 



Solubility : 1 in 3,800 cold, 1 in 2,500 boiling water ; 1 in 140 alcohol; 

 1 ill 10 chloroform ; 1 in 371 hot etiier ; soluble also in hot benzene, in 

 am\l alcohol, and in olive oil (1 in 100) ; but scarcely in cold ether, cold 

 benzene, or petroleum ether, and with difficulty in essential oils. 



It is removed from both alkaline and acid solutions by chloroform : 

 in tinces oulv by ether or benzene from alkaline solution ■ not at all by 

 petroleum ether. 



Precipitants : 



Alkaline hydrates 'J soluble in excess (Dragendorfl) : very .'•lightly 



( (Hiisemann). 

 Ammonia f the auim. pp is amorphous, but becomes crystal- 



3 line. 

 Alkaline carbonates. 



„ bicarbonates. 

 Tartaric acid prevents the precipitation by bicarbonate until boiled. 

 [Not by lead acetate, neutral or basic. | 

 Potassium ferrocyanide, neutral solution, yellowish-white, insol. on 



warming or in exce.ss (Dupuy) ; no pp. 1 in fiOO. 

 Potassium sulphocyanide, white Hocculent becoming crystalliue ; sol. 



alcohol ; no pp. 1 in ."lOO. 

 Silver-potassic cyanide. 



Potassium bichromate, pp. (gradual at 1 in 3,000, Dragendorff). 

 Chromic acid (5 per cent, solution to the neutral salt), pp. 

 Phospho-molybdic acid, pp : cloud at 1 in 200,('0O, slight opalescence 



at 1 in 500,000. 

 Phospho-antimonic acid, p)!. ; bluish- white at 1 in 1,000; cloud at 



1 in 5,000. 

 lodo-potassic iodide, kermes pp. up to 1 in 500,000. 

 Bismuth-])otassic iodide, orange-red — limit as phospho-molybdic acid. 

 Tannic acid, vellowish-white ; sol. in hydrochloric acid on warming ; 



cloud at 1 in 40,000. 



Picric acid, yellow becoming crystalline (sol. in excess, Dragendorff) ; 



reaction distinct at 1 in 100,(100 ; feeble cloud at 1 in 200,000. 

 Platinic chloride, lemon pp. ; insol. hydrochloric acid, 1 in 500. 

 Gold chloride, lemon pp. ; distinct cloud 1 in 100,000, feeble at 1 in 



200,0(10. 

 Cadmium potassic iodide, bair-like crystals up to 1 in 50,000 : clond 



at I m 10(1,000. 

 [Zinc potassic iodide, no pp., or very slight.] 

 Mercuric-potassic iodide, pp. ; cloud even at 1 in 000,(WO (? limit 



1 in 75,000, Dragendorff). 

 Mercuric chloride, white amorphous ; feeble at 1 in 10,000. Bed 



comjjound formed cm heating concentrated solutions. 

 Chlorine water, no coloration ; on addition of ammonia, white pp. 

 Sundry tests : 



Potassium persulphide, gradual white pp. on heating, 

 ("admium chloride, white crystalline pp. 

 Heated with tartaric acid, vapours yellow•^A.violet. 

 Many o.vidizing agents give red coloration. 

 Colour tests (negative) : 



Concentrated sulphnric acid ", 



„ ., „ with sugar I 



,. ,. with nitric acid I colourless. 



„ nitric acid j 



Acids in general i 



Frohde's reagent. J 



Per-iodic acid, iodine liberated. 

 (4o) ISOCINCHONINE A. (see (4i), Cinchonigine), CjjHjjN^O. Formed 

 like the corres]iondiug Isoquinine. Alkaline, laevo-rotatory ; M.P. 125°, 

 volatile in steam. 



Soluble easily in alcohol, ether, acetone, benzene, and chloroform. 

 Insoluble in water or alkalies. 



(4i) CINCHONETINE A. From Cinchonine by oxidation with potassium 

 permanganate, or lead peroxide and dilute sulphuric acid. A dark violet 

 substance. 



(4f) APOCINCHONINE A., Ci9H.>,K0. Prepared like the corresponding 

 Apoquinine, but no methyl group is eliminated as in the formation of 

 the latter. Crystallizes in anhydrous prisms ; M.P. 20i'° ; dextro-rotatory 

 ( + 1(W° in alcohol) ; alkaline, bitter, non-fluorescent. 



Soluble in alcohol, difficultly in ether or chloroform, and not in water. 



