RADIX JALAPiE. 445 



fibrous fracture; internally it is of a pale dingy brown or dirty white. 



It has a faint smoky, rather coffee-like odour, and a mawkish tasto, 

 followed by acridity. 



i 



croscopic Structure — Seen in transverse section, jalap exhibits 



M 



mgs 



many pieces are very regularly arranged. They are clue to the latici- 

 ferous cells, differing from the surrounding parenchyme only by their 

 contents and rather large size. These laticiferous cells traverse the 

 tissue in a vertical direction, constituting vertical bands, as may be 

 observed on a longitudinal section; the single cells are simply placed 

 one on the other, and do not form elongated ducts as in Lactiica or 



Tamxacum. 



The fibro-vascular bundles of jalap are neither numerous nor large ; 

 they are accompanied by thin-walled cells, so that fii^m woody rays do 

 not occur. Parenchymatous cells are abundant, and, on a longitudinal 

 fracture especially, if subsequently moistened, are seen to constitute con 

 centric layers. The laticiferous cells are always found in the outer par 

 of each layer. The suberous coat with which the drug is covered is 

 made up of the usual tabular cells. 



The parenchyme of jalap is loaded with starch grains; in the pieces 

 which have been submitted to heat in order to dry them, the starch 

 appears as an amorphous mass, and the drug then exhibits a horny 

 consistence and greyish fracture, instead of being mealy. Crystals of 

 calcium oxalate are frequently met with. The laticiferous cells contain 

 the resin of jalap in a scmi-iluid state, even in the dry drug; drops of 

 the resinous emulsion flow out of the cells, if thin slices are moistened 

 by any watery liquid. 



t 



^_sition— Jalap owes its medicinal efficacy to a 



resin, which is extractal>le by exliausting the drug with spirit of wine, 

 concentrating the alcoholic solution to a small bulk, and pouring it into 

 water. The resin precipitated in this manner is then washed and dried; 

 it is contained in jalap to the extent of 12 to 18 per cent.^ 



From this crude resin, which is the Rcsina jalapoi of the pharma- 

 copoeias, ether or chloroform extracts 5 to 7 {1'2, Umney) per cent, of a 

 resm which, according to Kayser,^ partiallysolidifies when in contact with 

 water in crystalline needles. We can by no means confirm Kayser's state- 



n^ient. 

 the name 



Maj 



assumption of water into amorphous (7om-o?ruZic^cK?,whic]i is readily 

 soluble in water. Both convolvulin and eunvolvulic acid are resolved by 

 moderate heating? with dilute acids, or with emulsin, mto erystallizable 



' Ouibourt obtained of it 17 per cent., percent, of resin B,^'»'f''*?" '«, "(.fP!"^';" 



tmney 21-5. Squibb 11 to IG, T. and H. that exposure of the sl.ceatubertotheari 



Smith .'„^,t more than 15," D. Hanbury 11 tlie process of drying favoms he foimatiou 



\«. 1^-8. Jalap gro^vn in B.mn afforded to of resin, by the o.xidat.on ot u hydrocarbon, 

 ^^arquart 12 per cent. ; a root cultivated at '^ Gmehn C7<.»HM/^;y. x^ i ( SG4) lo9 



A^"nich gave Wi.lnnmnn 22 per cent. ; from » As by Peroira, hhm. of Mai. Med. u. 



pants produced in Dublin W. G. Smith (1850) 14(>3. 

 got 9 to 12 per cent.; and fine tubers from ^ Gmelin, op. ut. xvi. \o\. 



"otacannuul in India yielded to one of us 18 



