44G CONVOLVULACE^. 



Convolvulinol, C-"H*''0^ and sugar. Convolvulinol in contact with 

 aqueous alkalis is converted into Convolvalinolic Acid, C-*^H*-0", 

 which is slightly soluble in water and crystallizable. 



When convolvulin or its derivatives is treated mth nitric acid, it 



yields several acids, one of which is the Sehacic A cid, (J'W^ \ moR 



which is to be obtained by treating castor oil or other fatty substances 

 in the same manner. Sebacic acid forms crystalline scales, soluble in 

 boiling water, melting at 128°. That from jalap was first thought to 

 be a peculiar acid, and therefore termed iponiic or ipomdeic acid. Its 

 identification is due to Neison and Bayne (1874). 



Convolvulin (dry) melts at 150° C., but a small amount of water 

 renders it fusible below 100° C. It is insoluble in oil of turpentine and 

 in annnonia. It dissolves in dilute nitric acid without becoming coloured 

 or evolving gas. Convolvulin possesses in a high degree the purgative 

 property of jalap, but this is not the case with convolvulinol. 



The other constituents of jalap include starch, inicrystallizable sugar, 

 ginn, and colouring matter. The sugar, according to Guibourt, exists to 

 the extent of 19 per cent. 



Commerce — We have no means of knowing to what extent jalap 

 is produced in Mexico. The imports of the drug into the United King- 

 dom amounted in 1870 to 109,951 lb. Very considerable quantities 

 have of late (1873) appeared in the London drug-sales. 



Uses— Jalap is employed as a brisk cathartic. 



Other kinds of Jalap. 



Besides true jalap, the roots of certain other Convolvula cfice of Mexico 

 have been employed in Europe, either in the form of jalapin, or as adul- 

 terants of the more costly, legitimate drug. The two following have 

 been extensively imported and have been traced to their botanical 

 source ; but there are others, of more occasional occurrence, the origm 

 of which has not been ascertained.' 



1. Lifjht, Fusiform, or Woody Jalap, Male Jalap, Orizaba Root, 

 Jalap Toj)s or Stalh, Puiyo macho of the Mexicans. , 



Ihis drug is derived from Ipomoia orizahensis Ledanois,^ a plant ot 

 Orizaba, which is but imperfectly known. It is described as a pubescent 

 clnnber, having a spindle-shaped root about two feet long of woody 

 and fibi-ous texture. The drug occurs in irret^ular rectangular or blocK- 

 Jike pieces, evidently portions of a very lar<^e root, divided transversely 

 and longitudinally. Sometimes it is more like true jalap, being in entire 

 roots, of smaller size, spindle-shaped, not spherical. It has a some\vhax 

 lighter colour than jalap, and much deeper longitudinal wrinkles. 1 ^^ 

 larger pieces often exhibit deep cuts from an axe or knife ; transv-erse 

 slices are of rare occurrence. Although generally less ponderous^ than 

 jaJap, the Orizaba drug is nevertheless of a compact and often hotn} 

 texture. From jalap it is easily distinguished by its radiated transverse 

 .section, and the numerous thick bundles of vessels which project as 

 woody hbres from the fractured surface. 



Sj 523 ' ^^'''''"■' '^'' ^''"'J"^-'' »• P^. 1. 2. (with unsatisfactory figures). 



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