VANILLA. 17s 
silky needles, which melt at 150°, and decompose on further 
heating, giving off a vapour which smells like vanilla (Wohler). 
It has a faint acid reaction and slightly bitter taste. When its 
sodium salt is heated with soda lime, methylvanillin is formed ; 
and zsovanillin when it is heated with dilute sulphuric acid to 
160°-170°*. The methylvanillin is slightly soluble in hot water, 
readily in alcohol, and crystallizes in needles which smell like 
vanilla. The isovanillin, which can also be formed by heating 
opianic acid to 160°-170° with dilute hydrochloric acid, crystal- 
hizes from hot water in monosymmetric prisms of vitreous lustre, 
which sublime when heated, undergoing slight decomposition ; 
its vapour has a pleasant smell, resembling that of vanilla and 
anise +. 
Processes for the production of vanillin from pyrocatechin and 
from guiacol have been patented in France by Alfraise, dated 23 
Dec. 1891 ¢. The process he describes for converting guiacol 
into aceto-ferulic acid and thence into vanillin does uot appear to 
be particularly novel, or to offer any solid advantage over already 
known methods: any economy in working expenses would be best 
known to manufacturers. 
It may here be remarked that whereas the abstracts of specifi- 
cations of French patents were formerly rather costly to obtain, 
abstracts in extenso are now supplied at moderate price by the 
Proprietors of the ‘ Revue de Chimie Industrielle,’ 53 bis, Rue des 
Grands Augustins, Paris. An abstract of the last-named specifi- 
cation is published in that Journal of May 1892, p. 154. 
This description is but a brief résumé of the very extensive 
literature of this valuable product. For an earnest study of the 
subject the reader is referred to the following works, but to an 
intending planter the pamphlet by Delteuil is a very fair guide :— 
DE LTEvIL, ‘ Etude sur la Vanille.’” Paris, 1874. 
JAILLET, “Culture et preparation de la Vanille.” ‘Repertoire de Phar- 
macie,’ vill. pp. 8357 & 411 (Aug. & Sept. 1880). 
‘Vanilla, its cultivation in India.’ J. E. O'Connor. Caleutta, 1875. 
‘Annals of Natural History,’ iii. p. 1. “On the production of Vanilla in 
Europe,” by Professor Morren. 
* Journ. Chem. Soe. 1876, i. p. 287. 
+ Tiemann, Ber. Deutsch. chem. Ges. viii. p. 1135. 
{ Brevet 218232, 
