JALAP 



353 



Microscopical Characters. Powdered jalap is characterised, when examined 

 under the microscope, by the abundant starch which may be intact or in any 

 stage of gelatinisation ; the grains are either simple or compound ; the former, 

 measuring mostly 25/x, to 40^,, are rounded or ovoid and exhibit concentric striae ; 

 compound grains may contain 2 to 6 constituents. Numerous globules of 

 resinous emulsion, varying in size, are evident or can be made evident by solution 

 of iodine in potassium iodide. There are occasional sclerenchymatous cells, 

 and fragments of vessels with areolated pits. Cluster crystals of calcium oxalate 

 are frequent. 



FIG. 183. Jalap 

 root. Small speci- 

 men, natural size, 

 showingthe trans- 

 verse lenticels. 



FIG. 184. Jalap root. Transverse sec- 

 tion. Slightly reduced. (Pharmaceutical 

 Journal. ) 



resin 



Constituents. The principal constituent of jalap is the 

 which can be separated by extracting the root with alcohol, concen- 

 trating the tincture, pouring it into water, washing and drying the 

 resinous precipitate. The drug contains in addition colouring 

 matter, sugar, starch, /3-methylsesculetin, ipurganol, a phytosterm 

 and calcium oxalate. t . 



The resinous precipitate obtained as described is known as jalap 

 resin.' The yield has varied from 2 to 22 per cent, of the drug ; 

 to 12 per cent, is often found. It is characterised by its partial solubi 



(about 10 per cent.) in ether. 



Jo 



