VANILLA. 650 



liquid surrounding the seeds. It was formerly regarded as cinnamic or 

 benzoic acid, and then as cumarin, until Gobley (1858) demonstrated its 

 peculiar nature. 



The admirable researches of Tiemann and Haarmann performed in 

 Hofmanu's laboratory at Berlin (1874-1876) have shown that vanillin 



r 0CH3 



IS constituted according to the formula Cm^ OH . It is the alde- 



iCHO 

 nyde of methyl-protocatechuic acid, and like other aldehydes yields a 

 crystallized compound with the bisulphites of alkalis. This is obtained 

 by shaking an ethereal extract (e) of vanilla, with a saturated solution of 

 bisulphite of sodium. The vanillin compound remaining in aqueous 

 solution is mixed with sulphuric acid and ether; the latter on evapora- 

 tion affords crystals of vanillin. They molt at 81°, and may be sub- 

 limed by cautiously heating them. Vanillin is but sparingly soluble in 

 cold water, and requires about 11 parts of it at 100° C. for solution; it 

 ■strikes a fine dark violet with perchloride of iron. 



The said chemists have further demonstrated that vanillin may be 

 formed artificially. In the sapwood of pines there occurs a substance 

 called Coniferin, C^^H-'^'O^ + 2 WO, first observed in 1861 by Hartig. 

 -by means of emulsin coniferin taking up H-0, can be resolved into 

 sugar and another crystallizable substance:— G^^^H^^Os + H20 = C«Hi-^0« 

 + C^"H^"Ol The second substance thus derived may be collected bj-- 

 means of ether, which dissolves neither coniferin nor sugar. By oxidiz- 

 ing it, or coniferin itself, by bichromate of potassium and sulphuric 

 acid. Vanillin is obtained. The latter has been for sometime manu- 

 factured in that way by Tiemann, but now eugenol (see p. 285) is used 

 Jor that purpose. Another source for vanillin is benzoin (p. 409). 



The amount of vanillin was stated by Haarmann and Tiemann to 

 be 1-G9 per cent, in Mexican vanillin, from 1-9 to 2'48 in the Bourbon 

 variety, and 2-75 in that from Java. The so-called Vanilloii affords 

 only 0-4 to 07 per cent, of vanillin. 



l^rom the above-mentioned ethereal solution (e), after it has been 

 deprived of vanillin, vanillate of sodium may be removed by a dilute 

 solution of carbonate of sodium. On acidulating the aqueous solution 



C OCff 

 crystals of vanillic add, C'H'-{ OH are precipitated. If the ether of 



fi, , (COOH ^ ^. . 



tne solution (e), after it has been treated with carbonate of sodium, is 

 allowed to evaporate, a mixture of fatty substances and a resm are 

 Obtained. The latter has a peculiar odour, somewhat suggestive of 

 castoreum; vanillic acid is almost inodorous. ^ 



Leutner (1872) also found in vanilla fatty and waxy mattei; llvS 

 resm 40, gum and sugar 16-5 per cent.; and obtained by incineration of 

 the drug 4-6 per cent, of ash. 



. Production and Commerce— The chief seats of vanilla-production 

 in Mexico are the slopes of the Cordilleras, north-west of Vera Cruz 

 the centre of the culture being Jicaltepec, in the vicinity of ^autla. 

 ^he finest specimens were contributed in 1878 to the Pans Exhibition 



^Cult 



R^. nV '^" ^'anUUer m/ Mexiqve, in the 

 ^" C-o^wj/oZr, ii. (1849) 383-390; also J. 



W von Miiller, Rfisen in . . . Mexico, n. 

 (Leipzig, 18G4) 284-290. 



