IMCTIONAUV OF THE ACTIVE PRINCIPLES 01' PLANTS. 



Ferric chloride, no colour till boiled with alkali, then blood-red 



(sulphocyanide test). 

 Silver nitrate, white pp., becoming black from production of silver 



.sulphide. 

 Fehling's solution, reduced, some cupric sulphide being formed. 

 Jlercuric chloride, pp., glucose being left in solution. 

 Concentrated nitric acid, transient blood-red. 



(i) SINAPINE-THIOCYANIDE A. (Sulphosinapisine, Sulphosinapine ; the 

 thiocyanide was formerly mistaken for Sinapine), C,|.H.,.,NO-"HSCN 

 (Gerhardt) ; glittering prisms ; M.P. 130°, recrystallizing on cooling ; 

 neutral reaction (free Sinapine is alkaline), bitter. ( Free Sinapine 

 rapidly decomposes : not separated pure either by alcohol or ether. 



Soluble in water and alcohol (yellow solutions) ; not in ether, carbon 

 bisulphide, or turpentine. 



Alkaline hydrates dissolve yellow. 



Ferric chloride, blood-red coloration on warming. 



(.•) POTASSIUM MYRONATE G., Ci„H,8KNSoO,u : crystallizes in silky 

 prisms, fusible, neutral, bitter. (The free acid decomposes readily, with 

 production of sulphuretted hydrogen ; it has acid reaction, with bitter 

 and sour taste). Myrosin converts the glucoside to glucose, Allyl- 

 thiocyanide, and acid ]iotassiura sulphate. 



Soluble ill water, with difficulty in alcohol. Insoluble in ether, chloro- 

 form, or benzene. 



Precipitated by neutral lead acetate, yellowish-white pp., soluble in 

 acetic acid. 



(d) SINCALINE. by action of alkalies on Sinapine ; crystalline, non- 

 volatile, powerfully alkaline like potafsic hydrate ; absorbs carbonic 

 acid. 



§ 208. SOLANUM various {Solanacea), e.r/., S. nigrum (Nightshade), 

 substance («) ; S. tuberosum (Potato, the leaves and -shoots), (a) and (c) ; 

 S. dulcamara (Bittersweet), (a), ( / ), Geissler, ArcJiir. d. Pliarm., [3], 7, 

 289, 1875 ; S. grandiflora var. pulvernlentum (Wolf-fruit of Brazil), 

 investigator, H. Freire, Coiiijit. Eei.dii, 105, 1,074, (r/) ; S. paniculatum 

 (the fruit), F. v. Greene, substance (c). See also Atropa group for other 

 members of the Solanacea: 



(a) SOLANINE A.-G., Cj.H-jNO,., (Hilger) or Cs.H^.NO,, (Firbas) ; 

 crystallizes in four-sided prisma; M.P. 235", with some sublimate in 



needles; feebly alkaline ; taste bitter and hot. Dilute acids resolve into 

 sugar and Solanidine. Salts react acid. Sodium amalgam produces 

 butyric acid and nicotine.' 



Soluble scarcely in water, 1 in 8,000 boiling (the salts are soluble), in 

 125 boiling alcohol of sp. gr. 0-83!.) (giving crystals on cooling), in amyl 

 alcohol, 4,000 ether. Benzene dissolves traces. 



Removed from aqueous solutions by amyl alcohol. 



Reactions : 



Alkaline hydrates ) , 



, ■ ■' y amorphous pp. 



Ammonia J ' ' '^ 



Tannic acid, pp. ; at 1 in 3,000, flocks after 24 hours. 



[Picric acid, not dilute. 



Platinum chloride, not dilute.] 



Gold chloride J , j . j 



Silver nitrate f 



[Fehling's solution, not reduced.] 



Silver pota.ssium cyanide, gradually amorphous pp. 



[Potassium bichromate, not 1 in 3,000.] 



Phosiiho-molybdic acid, light yellow pp. 



[lodo-potassic iodide, not 1 in 3,000.] 



[Bismuth-potassic iodide, pp. only if concentrated.] 



I Cadmium-potassic iodide, not dilute.] 



[Mercuric-potassic iodide, not 1 in 3,000]. 



[Mercuric chloride, not 1 in 3,000.] 



Colour tests : 



Concentrated sulphuric acid, light reddish-yellow. 



„ ,, „ with potassium bichromate, light blue. 



Trace of Solanine-|-l per cent, sulphuric acid evaporated on watch- 

 glass, gives four-sided pi'isms, which on warming become successively 

 red, purple, brownish-red, and, on cooling, violet, blackish-blue, 

 green (colourless crystals still present). 



Concentrated sulphuric acid with nitric acid, light reddish. 



Nitric acid added to the solution in sulphuric acid after 10 hour.*, 

 light yellow. 



Nitric acid alone, colourless, then purple, finally colourless. 



Concentrated hydrochloric acid, yellow. 



FriJhde's solution, cherrv-red-v>-brownish-red-<~yellow ; after 24 hours 

 greenish-yellow with black flocks. 



Sulphuric acid and alcohol, red on warming. 



