272 VANILLA PLANIFOLIA 



General Characters, Varieties, and Composition. The vanilla of 

 commerce occurs in the form of fleshy, cylindrical, somewhat 

 flattened, flexible, stick-like fruits, varying in length from 4 to 8 

 inches, and in thickness from about 5 to 4 an inch. The fruits 

 taper in some degree towards their extremities, and are more or 

 less bent at their base. Externally they present a dark brown 

 or blackish colour, and a greasy shining surface, which is finely 

 furrowed in a longitudinal direction, and often covered with an 

 efflorescence of small whitish crystals. Each fruit is commonly 

 split into two unequal parts (valves), and exhibits in its interior a 

 multitude of very minute, hard, glossy, black seeds, imbedded in 

 a soft, thick, brownish-black, oily pulp. Vanilla has a strong, 

 peculiar, very agreeable, aromatic odour, and a warm, sweetish, 

 aromatic taste. The interior portion is the most fragrant. 



There are several varieties of vanilla found in commerce, as 

 Mexican or Vera Cruz, Bourbon, Mauritius, Java, La Guayra, 

 Honduras, Brazilian, &c. The finest kind is Mexican Vanilla ; 

 of which, however, we have different qualities, and its production 

 has much declined of late years. These varieties of vanilla are 

 doubtless derived from different species of Vanilla; the finest 

 vanilla, such as the Mexican, is commonly said to be the produce 

 of Vanilla planifolia, the species now under description. The 

 official plant is, however, as already noticed, Vanilla aromatica, 

 Swartz. 



The delicious fragrance of vanilla is due to a peculiar substance, 

 called Vanillin or Vanillic acid, which exists in the proportion 

 of about 1 per cent. Vanillin is frequently found in the form of 

 minute crystals in the surface of, or inside, the fruit ; or it is 

 dissolved in the viscid oily pulp in which the seeds are imbedded. 

 When pure vanillin is in the form of hard, colourless, 4- sided, 

 acicular prisms, with a vanilla odour, and somewhat pungent taste. 

 It is very soluble in alcohol, ether, and the fixed and volatile oils ; 

 and its solutions feebly redden litmus. It is soluble with diffi- 

 culty in cold water; but it dissolves in 11 parts of boiling water, 

 but is again deposited on cooling. Vanillin fuses at -about 180, 

 and may be sublimed unchanged. Vanillin has recently been 



