560 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



reprecipitated on the addition of diluted sulphuric acid. The 

 saponification number of genuine scammony resin is from 238 to 

 240.5. 



Constituents. From 75 to 95 per cent of a glucosidal resin (scam- 

 monin), which is completely soluble in ether; gum, 5 to 8 per cent; 

 ash, not more than 3 per cent. Scammonin is apparently identical 

 with the resin in Ipomcea orizabensis and the ether-soluble resin in 

 jalap. It occurs as a white powder, which on treatment with alkalies 

 yields the glucoside scammonic acid. The latter on hydrolysis 

 decomposes into scammonolic acid and glucose. An anhydride of 

 scammonolic acid, scammonol, some valerianic acid and sugar are 

 formed on treating scammonin with mineral acids. The peculiar 

 cheese-like odor of the resin is due to the formation of a volatile, 

 fatty acid during the drying process. 



Adulterants. Scammony is adulterated with inorganic sub- 

 stances, various starchy products, foreign resins, such as guaiac, 

 and an extract of the juice of the root of Convolvulus althseoides, 

 a plant indigenous to the countries of the Mediterranean. 



Montpelier Scammony is the natural exudation of Marsdenia 

 erecta (Fam. AsclepiadaceaB), a plant indigenous to southern Europe. 

 It contains 50 to 60 per cent of starch, 10 to 21 per cent of resin, 

 and yields 11 to 18 per cent of ash. 



Literature, Power, Jour, Chem. Soc., 1912, p. 398. 



HYDROPHYLLACEJE, OR WATERLEAF FAMILY 



A family of about 160 species of herbs and shrubs, mostly indigen- 

 ous to western North America. The leaves are opposite, the flowers 

 are regular and 5-merous, and the fruits are capsular. From the 

 supposition, that in the springtime the leaves of the plants were filled 

 with water, the family received its name. There is no special ana- 

 tomical structure indicating on what this might be based. The 

 leaves differ in structure very little from those of other plants. The 

 leaves are bifacial and the stomata usually occur only on the lower 

 surface, being surrounded by an indefinite number of ordinary epi- 

 dermal cells. The non-glandular hairs are usually unicellular, rarely 

 uniseriate, occasionally encrusted with calcium carbonate, or may 

 contain a cystolith-like body. Glandular hairs are widely distributed 

 and are of a number of distinct types. Calcium oxalate occurs in 

 the form of rosette aggregates. The general structure of the plants 

 of this family is given under Eriodictyon. 



