420 CONVOLVULIN. 



cold water, easily soluble in alcohol; fuses at 190. 

 With dilute acids it yields sugar and/mxefa'n, C 10 H 8 5 . 



11. Phillyrin. 



Q27JJ34QH. 



Contained in the bark of Phyllyrea latifolia. Color- 

 less crystals ; difficultly soluble in cold water ; fusing at 

 160. Dilute acids resolve it into sugar and philly- 

 genin, C 21 H 24 6 . 



12. Daphnin. 

 C 31 H 34 19 + 4H 2 0. 



In the bark of Daphne alpina and Daphne meze- 

 reum. Colorless, transparent prisms ; fusing at 200 ; 

 insoluble in cold water and in ether, easily soluble in 

 hot water and alcohol. Emulsin or dilute acids resolve 

 it into sugar and daphnetin, C 19 H 14 9 . 



13. Myronic Acid. 

 C 10 H 19 NS 2 10 . 



In the seed of black-mustard in the form of the potas- 

 sium salt. This can be extracted from the residue by 

 means of water after the powdered seed has been 

 boiled with alcohol. Small, silky needles ; easily sol- 

 uble in water. In contact with myrosin, a ferment 

 contained in mustard seed, and heated with baryta- 

 water, it is decomposed into allyl mustard-oil (p. 215) 

 and potassium bisulphate. Its solution gives a white 

 precipitate with silver nitrate, C 4 H 5 NS0 4 Ag 2 , which, 

 when treated with sulphuretted hydrogen, yields silver 

 sulphide, sulphur, free sulphuric acid, and allvl cyanide 

 (p. 120). 



14. Convolvulin (Rhodeoretiri). 



C 31 H 50 16 . 



In jalap root (of Convolvulus schiedeanus). The root 

 is first thoroughly exhausted with boiling water, then 

 treated with alcohol ; the alcoholic solution decolor- 



