80 



UK TioNAKV or Tin; active i'kincii'lks of plants. 



Soluble in alcohol and ether ; with difUoulty in water. 



Ammonia gives bluish-green solution. 



Lc:i(i acetate, red p]). 



( f) PIMARIC ACID, from resin, has bitter taste. 



Soluble ill hot alcohol or hot ether ; not in water. 



ij 171!. PIPER longum (Pepper), P. nigrum, P. ciibebum, P. caudatum ; 

 J'iperaci ic. Schinus mollis, Tereli'nitliarcjr ; alkaloid (a). The fruit and 

 seed of P. longum, 7 to 9 per cent, of («), besides (h). 



(,i ) PIPERINE A., C,7H,„NO., or 



CH,<Q>CcH,CH:GH-CH:CHC0(C5Hi„X); 



mouocliiiic prisms ; M.P. 100' (l'28°-12!l-5°, Dupuy) ; neutral reaction, 

 almost tasteless if pure, optically inactive. The salts dissociate with 

 water. 



Soluble in 30 parts cold alcohol, ] part boiling, Gl) cold ether ; also in 

 chloroform, benzene, and somewhat in petroleum ether ; difficultly in 

 water even boiling. 



Removed in part from wid solutions by benzene and jietroleum ether. 



Reactions : 



Ferric chloride, pp. (hydrochloric solution). 



[Platinum chloride, pp. only if concentd. ; double salt very soluble.] 

 Phos]iho-molybdic acid, brown pp. 



[Phospho-antimouic acid, yellow coloration in dilute solutions.] 

 (Jaduiium-potassic iodide, pp. 

 Mercuric-potassic iodide, yellowish-white pp. 

 [Mercuric chloride, pp. if concentrated.] 

 Colour tests : 



Concentrated sulphuric acid, yellow; green in "io hours. 



„ „ „ with nitric acid, gradually green. 



Nitre added to the solution in sulphuric acid after 10 to lii hours, the 



greenish-brown solution becomes reddish-brown. 

 Xitric acid alone, orange changing to yellowish green (dissolves 



slowly). 

 Frohde's solution, yellow, turning brown to nearly black. 



(h) PIPEfilDINE A. (Hexahydro-pyridine), CjH„X : a liquid with 

 peppery and ammoniacal odour, burning taste ; boiU at lUli ; powerfully 

 alkaline, giving crystalline salts. 



Soluble in alcohol, and in all proportions with water. 



Reactions with metallic salts like ammonium hydrate. 



Bismuth potassic iodide gives a pp. with the hydriodide. 



§177. PISCIDIA erythrina; Lfiiininnoxif —PiijiiUiinacea: The root- 

 bark. Investigator : K. Hart. 



PISCIDIN 1?., C,,,,H.„08 ; prismatic crystals. 



Soluble in hot alcohol, also in benzene and chloroform ; with difficulty 

 in ether ; not in water. Dilates the pupil. 



§ 178. PLUMERIA lancifolia (Agoniada bark) ; A/iort/iiarfu . In- 

 vestigators : Peckolt, .I/vAh; Pliariii., [2], 192, lU ; and Geutber. Used 

 as febrifuge. 



{(i) AGONIADIN G., Ci„H,jOc (Geuther) ; crystallizes in radiating silky 

 needles; JI.P. l.'io" (no sublimate) ; very bitter. Dilute acids produce a 

 brown amorphous substance and sugar. 



Soluble with difficulty in lioiling water, scarcely in the cold ; not readilj' 

 in cold alcohol, but better in warm ; dissolved also by a mixture of ether 

 and alcohol, and by carbon bisulphide ; not by chloroform or petroleum 

 ether. 



Reactions : 



Alkaline hydrates, dissolve brown on warming. 

 Ammonia, dissolves cold. 

 [\ot precipitated b^' lead acetate, neutral or basic] 

 Tannic acid, pp. gradually. 

 Ferric chloride, pp. 



[Xot precipitated by other metallic salts.] 

 Colour tests : 



Concentrated sulphuric acid, dissolves light yellow, changing to green 

 „ „ „ with nitric acid, gradually yellow. 



„ nitric acid, golden-yellow. 



,, hydrochloric acid, dissolves colourless. 



{h) AGONIAPICRIN B. ; brownish amorphous, neutral, bitter, not 

 poisonous. 



Soluble in water, alcohol and ether. 

 Reactions : 



Tannic acid, brown pp. 

 [Ferric chloride, brown coloration.] 

 Platinum chloride, dark brown pp. 

 § 17!i. PODOPHYLLUM peltatum (May Apple) ; Ranuiiculareo'. In- 

 vestigator : Podwyssotski,.4rc/(/i' Phannak. ti.e.i'per. Pathol., 13, 29. 



