132 ODOROGRAPHIA. 
CHAPTER VIL. 
ODOUR OF THE HAYFIELDS. 
Tue Opour or CouMARIN. 
Tue fragrant bean called Tonka, or Tonquin bean, is the seed 
of the Dipterix odorata, a large leguminous forest tree, native of 
Cayenne. In British Guiana this tree is called “ Kumara,’ from 
which name the word “ coumarin ” is probably derived. It grows 
plentifully in some localities, especially above and on the islands 
in the rapids of the Esquibo River. The seeds contain a fine 
fixed oil obtainable by expression, which is used by the natives of 
the colony as a perfumed hair-vil. This oil may have been the 
basis of a once well-known hair-restorer called ‘ Balm of 
Columbia.” The tree is also an inhabitant of Martinique. The 
average height of it is 70 feet, but in Guiana it is said to attain 
90 feet. The pods contain but one seed, which is shaped like an 
almond, but much larger, and covered with a shining black skin. 
The fruit-pod does not open naturally at maturity, as does that of 
most leguminous plants. The seed when ripe and detached from 
the stalk rapidly acquires a powerful and aromatic odour, sug- 
gestive of new hay, although while actually growing it is nearly 
odourless; the hardening of the mature seed developing coumarin, 
its odorous principle, the small white crystals of which are visible 
beneath the covering of the kernel and between the lobes. The 
evaporation of this substance is prevented by the fixed oil in the 
kernel. The perfume is extracted in the form of a tincture, by 
cutting the beans very small and macerating them in spirit of wine. 
Coumarin was discovered in the Tonka bean in 1825 by 
Boullay and Boutron-Charland *, and was studied and analysed 
* Journ. de Pharm. xi. p. 480. 
