VANILLA. big 
precipitated benzoic acid separated by filtration, the acid filtrate 
shaken with ether and the ether evaporated spontaneously. The 
impure vanillin thus obtained is purified by re-crystallization 
from water, from which it separates in long thin white needles, 
turning yellow on exposure to the air*. 
Vanillin from Asafetida.—The actual preparation of vanillin 
from asafcetida is described by Schmidt as follows + :—An ethereal 
extract of the gum-resin is shaken with a strong solution of 
sodium bisulphite, adding to the solution excess of sulphuric 
acid, and after driving off sulphurous acid, extracting the liquid 
with ether. Upon evaporation of the ether, crude vanillin is left 
as a residue, which after purification corresponds in every respect 
with vanillin from other sources. The possibility of deriving 
vanillin from asafoetida was suggested fifteen years ago by Tie- 
mann, who showed the connection between that compound and 
ferulic acid. Vanillin has an acid reaction and forms salts, 
which have been investigated by Carles, and by Tiemann and 
Haarmann. By the action of an ethereal solution of acetic 
anhydride upon the sodium salt of vanillin, a coumarin-like body 
is produced which has been: named “ vanillin-coumarin.” This 
body when boiled with caustic potash is converted into an acid 
identical with the ferulic acid obtained from asafcetida f. 
Vanillin has been obtained by heating guaiacol § with caustic 
* Ber. Deutsch. chem. Ges. 1878, p. 1634. 
+ Archives der pharmacie, June 1886, p. 454. 
t Pharm. Journ. [3] vi. p. 815. 
§ Guaiacol.—Produced from the products of the dry distillation of guaiac 
resin, which is a natural exudation or the result of incisions made in the bark 
of the Hujacum tree, Guajacum officinale, a tree growing in Jamaica, St. Do- 
mingo, and other West Indian Islands. In the Island of Gonave, near Port-au- 
Prince, another method is used: a log is supported in a horizontal position 
above the ground by two bars, and each end of the log set on fire, the melted 
resin running from a large incision which has previously been made in the 
middle. Guaiacum resin is a brittle dark green to brownish-black mass, which 
readily dissolves in alcohol. When submitted to dry distillation it yields 
guaiol or tiglic aldehyde, guaiacol, creosol, and pyroguaiacin. 
When the crude oil obtained by distillation is washed with water and 
rectified at a moderate heat, guaiacene passes over first, and afterwards, when 
the heat is increased, the guaiacol distils. It may be purified by repeated 
rectification or by dissolving it in potash and boiling it with water as long as 
any light oil passes over, then mixing it with sulphuric acid in quantity not 
quite sufficient to combine with the whole of the potash, redissolving the 
