172 ODOROGRAPHIA. 
soda and chloroform*; and from olivil + the crystalline con- 
stituent of the Lecca gum, or resin of the wild olive t, which is 
used in Italy as Incense; also by the oxidation of ferulie acid, 
which can be prepared on a large scale without difficulty §. 
Vanilin has been obtained from opium. Narcotin is first 
extracted and converted into opianic acid by heating 100 grammes 
with 1500 grammes of water and 150 grammes of sulphuric acid 
until the mixture boils; 150 grammes of finely powdered pyrolu- 
site (corresponding to 90 grammes of manganese dioxide) are 
then added somewhat rapidly and the hot solution filtered. 
Opianic acid separates out on cooling and is purified by crystal- 
lization, It is slightly soluble in cold, readily in hot water, 
alcohol, and ether, and crystallizes in thin narrow prisms, or 
separated oil in potash and boiling the solution in a retort till the milky oil 
which passes over becomes perfectly clear on the addition of a small quantity 
of potash, again separating the oil by sulphuric acid and drying it in vacuo 
over sulphuric acid. It is a colourless oil, having a sp. gr. of 1119 at 22° 
(Sobrero), 1:125 at 16° (Volckel) ; it boils at 210°. 
Guaiacol can also be obtained from beech-wood tar. The crude compound 
obtained from beech-wood tar creosote is repeatedly shaken with moderately 
strong ammonia, washed, and rectified. The oil is then dissolved in an equal 
volume of ether, and a small excess of alcoholic potash (concentrated) added to 
it. The potassium salt separates out and is then re-crystallized from alcohol 
and decompased by dilute sulphuric acid, 
* Bull. Soc, Chim. ix. p. 424. 
t Scheidel, Ber, Deutsch, chem, Ges, xviii. p. 685. 
{ Olivil, C,,H,,0;, is the crystalline constituent of the resin of the wild olive. 
It forms a thick vapour on heating and has a pleasant odour resembling those 
of benzoin and cloves. It is employed in Italy for the fumigation of sick 
rooms. In order to obtain the olivil, the resin is extracted with ether and the 
residue treated with boiling aleohol. The olivil, which separates on cooling, is 
washed with cold dilute alcohol and re-crystallizes from alcohol. It forms 
white needles which are odourless, and have a sweetish, bitter taste, melt at 
120° and solidify to an amorphous mass, which forms a strongly electrified 
powder on trituration. This mass melts at 70°, but after re-crystallization from 
alcohol, regains the original melting-point. It crystallizes from hot water in 
stellate groups of prisms, which contain one molecule of water. It is readily 
soluble in alkalies and precipitates the metals from solutions of gold chloride 
and silver nitrate. On dry distillation it yields an oily liquid, to which Sobrero 
has given the name of pyro-olivilic acid (Ann. Chem. Pharm. liv. p. 67). It 
has the composition and properties of eugenol and is either identical with this 
or iso-eugenol., 
§ Ulrich, Ber. Deutsch. chem, Ges, xviii. ref, 682. 
