EUPHORBIUM 



429 



The drug itself is very brittle, breaking readily between the fingers ; 

 internally it is of a dull yellowish brown colour. It has no parti- 

 cular odour, but an extremely acrid taste and the powder, if inhaled, 

 produces violent sneezing. It is partially soluble in 90 per cent. 



alcohol (62 per cent.), in 

 ether (56 per cent.), and 

 in water (32 per cent.), 

 but almost completely in 

 glacial acetic acid. Petro- 

 leum spirit dissolves about 

 36 per cent., and the 

 solution, carefully poured 

 over sulphuric acid con- 

 taining one drop of nitric 

 acid in 20 c.c., develops 

 a blood-red zone ; this re- 

 action is characteristic of 

 euphorbium. 



Constituents. E up h o r - 

 bium consists chiefly of 

 euphorbone (40 per cent.), 

 euphorbo - resene (20 per 

 cent.), euphorbic acid (07 



FIG. 237. Laticiferous cells in the stem of 

 Euphorbia resinifera. p, parenchyma-; 

 m, laticiferous cells. Magnified. 

 (Tschirch.) 



FIG. 238. Euphorbium. 1, pair 

 of stipules ; a, and b, stipules 

 covered with gum-resin ; 2, 

 fruit ; c, fruit covered with 

 gum-resin. Natural size. (Vogl.) 



per cent.), calcium malate (25 per cent.) together with an intensely 

 acrid substance which has not yet been isolated, vegetable debris, 

 &c. ; it yields about 5 per cent, of ash. 



Euphorbone crystallises from acetone in colourless, odourless, and tasteless 

 acicular crystals melting at 115-116. 



Euphorbo-resene is yellowish brown, amorphous, and tasteless. 



The acrid substance to which the physiological action of the resin is due is 



