80 



But to effect a complete separation, it is bettei' to previously 

 mix the oil with potash, or soda-ley, which combines with the 

 acid, allowing the neutral or basic oil to distil first. By adding to 

 the residue in the retort afterwards sulphuric or better phos- 

 phoric acid and distilling again, the acid oil is obtained pure. 



[Ustimation of Essential Oils according to Osse. — Treat five 

 gi'ammes of the finely pulverised substance cold with twenty- 

 five cubic centimeters of petroleiim ether (of a boiling-point not 

 above 40°), shake for a few hours, let subside, evaporate one cubic 

 centimeter of the clear liquid in a current of aii*, weigh the re- 

 maining mixture of wax or fat and oil, evaj^orate the volatile oil 

 at 110° and weigh again. The latter weight deducted from the 

 first gives the amount of the essential oil.] 



[EucalyiltllS Constituents. The leaves of Eucalyptus 

 globulus, according to H. Weber, contain besides the volatile oil 

 the following substances: — 1. A white body, crystallising in 

 needles, mixed with a resinous, amorphous mass, both of acid 

 reaction, 2, An acid, yellow resin of bitter taste, 3. Euca- 

 lyptic acid, precipitable by lead salts. 4. Eucalyptin, a neutral, 

 crystallisable, bitter substance, soluble in ether and alcohol, partly 

 in water. Used as a remedy against interraittent fevers.] 



Eucalin. See Melitose, . 



Eugenic Acid=CARYOPHYLLic Acid, 



Euo'enin=:C2o H12 O4 (isomeric with cuminic acid and caryo- 

 phyllic acid). Separates slowly from the tm-bid aqueous 

 distillate of cloves overcharged with volatile oil. — Delicate 

 white, pellucid, pearly laminae, turning yellow by keejDing; of 

 a faint odour of cloves; dissolves readily in alcohol and ether; 

 assumes, like caryophyllic acid, a blood-red colour with cold nitric 

 acid. 



Eupatoriu, Bitter ingredient of the leaves and flowers of 

 Eupatorium cannabinum (probably obtainable from numerous 

 species of this genus.— F. v. M.) It is obtained by precipitating 

 the aqueous extract with slaked lime, digesting the precipitate, 

 after it has absorbed carbonic acid from the air, with alcohol and 

 evaporating the tincture to dryness. — White powder of a bitter 

 and pungent taste, insoluble in water, soluble in absolute alcohol 

 and in ether, said to yield a crystalline salt with sulphuric acid. 



EupllOl'bium, The hardened milky juice of several species of 

 the genus Euphorbia. Dirty-yellow, white inside, brittle, porous 

 lumps without smell and of excessively aciid taste. Contains 

 about 60% resin (EuphorbinzrCoo Hic 0), 14% wax, 5% caout- 

 chouc and various salts. 



