VANILLA. 169 
Shortly after the above discovery, it was found that vanillin 
could be artificially produced from oil of cloves. On the 18th of 
March, 1876, a patent was taken by de Laire in France* for this 
purpose. According to his specification the process is thus 
described :—“ The starting-point of the manufacture is the 
preparation of Kugenol; I obtained this from oil of cloves, which 
contains it in large proportion. I dissolve one kilo of this oil in 
four or five kilos of ether, and agitate the mixture with a weak 
aqueous solution of sodium hydrate, which absorbs all the 
eugenol ; the hydrocarbon which constitutes the rest of the oil 
remaining in solution in the ether. I separate the sodium solu- 
tion and saturate it with sulphuric acid to set free the eugenol, 
which I collect by agitation with ether. On evaporation of the 
ether, the eugenol is left pure. This body is then heated for two 
or three hours with an equivalent proportion of acetic anhydride 
in an apparatus connected with an inverted condenser, being 
thereby converted into acetyleugenol. The mass is then allowed 
to cool, and when cold is agitated with several times its weight 
of water. The liquid is then gently warmed, and to it is gradually 
added a weak solution of potassium permanganate (1500 grammes 
of permanganate altogether). 
“The hydrate of manganese is separated out by filtration, the 
remaining solution gradually saturated with soda and its volume 
reduced by evaporation. When the liquid is cold it is acidified 
with sulphuric acid and agitated with ether, which takes up the 
vanilli, On evaporation of the ether the vanillin remains in 
crystals.” 
A patent was taken out in England for the production of 
vanillin from oil of cloves by Dr. Tiemann on the 20th of April, 
1876. The process, which is very similar to de Laire’s, taken 
out a month previously in France, is described as follows in the 
specification + :— To separate the two constituents (oil of cloves 
and the hydrocarbon) one from another, the oil is diluted with 
three times its volume of ether. The etheric solution is then 
agitated with a weak solution of hydrate of sodium or potassium, 
which takes up all the eugenol and leaves the indifferent hydro- 
carbon in the ether. After having acidulated the alkaline 
* Brevet 111950. + No. 1661. 
