JALAP 



555 



and in some cases more or less swollen; resin secretory-cells yellowish 

 brown; sclerenchymatous fibers few, with simple pores. Tubers 

 deficient in resin are lighter in color, contain more starch and less 

 calcium oxalate. 



Constituents. Resin 8 to 12 per cent, 85 to 90 per cent of which 

 is insoluble in ether. Power and Rogerson (J. Am. Chem. Soc., 

 1910, p. 80) isolated from the ethereal extract of the resin a new 

 dihydric alcohol (ipurganol) which crystallizes in colorless needles 

 and yields color reactions similar to those given by the phytosterols. 

 From the chloroform extract they isolated a small amount of /3- 

 methylaesculetin. The petroleum ether extracts showed the pres- 



pr 



FIG. 238. Jalap: pr, parenchyma containing unaltered starch grains; pr', 

 parenchyma containing swollen starch grains; a, starch grains; K, rosette 

 aggregates of calcium oxalate; m, globular mass of resin; sp, fragment of 

 tracheae showing bordered pores. After Vogl. 



ence of palmitic and stearic acids in the free state. On treatment 

 with alkalies and dilute sulphuric acid some of the extracts of the 

 resins yield a number of acids and there are indications that a por- 

 tion of the chloroform extract of the resin is of a glucosidal nature. 

 The alcohol extract of the resin, which represented 38.8 per cent of 

 the total resin, was obtained, after treatment with animal charcoal, 

 in the form of a nearly white powder. When subjected to alkaline 

 hydrolysis with baryta, this alcohol extract yielded a number of 

 organic acids together with a hydrolyzed resin of very complex 

 composition. Jalap also contains a volatile oil, calcium oxalate, 

 starch, gum and sugar. 



Allied Plants. Brazilian Jalap. During the war several jalap 

 substitutes were offered. One of these, known in Brazil as Batata de 



