420 CONVOLVULIN. 



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

 &quot;With dilute acids it yields sugar &nd.fraxetin, C 10 H 8 5 . 



11. Phillyrin. 

 C 27 H 34 On 



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. DapJinin. 

 C 31 H 34 19 + 4IPO. 



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 IKN&quot;S0 4 Ag 2 , which, 

 when treated with sulphuretted hydrogen, yields silver 

 sulphide, sulphur, free sulphuric acid, and allvl cyanide 

 (p. 120). 



14. Convolvulin (Rhodeorethi). 

 C 31 IF0 16 . 



In jalap root (of Convolvulus schiedeanus). The root 

 is first thoroughly exhausted with boiling water, then 

 treated with alcohol ; the alcoholic solution decolor- 



