SOIL AND VEGETATION. 67 



mud volcano in Savanna Grande afforded, on examination, 

 results very similar to the preceding, seeming- to indicate a 

 common source and origin. What is worthy of note in the 

 waters of the mud eruptions," adds the Doctor, " is the presence 

 of iodine, a substance of high medicinal powers. Containing it, 

 they may be deserving of trial, and may prove efficacious in all 

 those ailments in the treatment of which iodine has been found 

 to be beneficial." 



The vegetation of wild plants furnishes a good criterion 

 whereby to judge of the various degrees of fertility or barren- 

 ness of soils. The single family of palms affords sufficient 

 accurate indications of the quality of the land and of its adapta- 

 bility, or otherwise, to the growth of our various staples : as 

 instances — the Carat is indicative of the best soil, and of its 

 suitableness for the production of sugar ; the Mountain-cabbage 

 is a sure characteristic of good land, adapted to the cultivation 

 of cacao and coffee ; the Attalea speciosa, of a light rich loam, 

 particularly well suited to the production of " ground-provi- 

 sions ; " the Groo-groo, on the other hand, grows in dry silicious 

 lands ; the Timite generally in low sandy tracts ; the Cocorite 

 and Palma Real in the worst soils. Any land producing the 

 Carat (Coper moid) and Mountain-cabbage (Oreodoxa) Palms, 

 the Wild Fig-tree (Ficus), Wild Plum-tree (Spondias), the Cedar 

 (Cedrela), Balizier (Heliconia), Sand-box tree (Hura), &c, 

 may be pronounced good. Wherever these plants grow in 

 abundance, the soil is very fertile ; the Carat, wild Fig-tree, 

 and Cedar, however, are particularly characteristic of superior 

 lands. The soil is of excellent quality where the Fig-tree, 

 Mountain-cabbage, Plum-tree, Cedar, and Baliziers are plentiful; 

 it may also be considered good whenever any one of the above 

 species is not wanting. On the contrary, wherever the Cocorite, 

 Manaco, Timite, and Groo-groo (Palms), the Mulatto-tree 

 (Cassia), Bois-sang (Fismia), the Fox-tail grass, Cortaderas 

 (Scleria), Caratas, Pine-apple, and Melastomaceous plants grow 

 in abundance, the soil may be pronounced poor and unproduc- 

 tive. The Poui (Tecoma) Balata (Ackras), Carapa, or Crapaud 

 (Carapa), and Guatecaro (Levy this) thrive both in good and bad 

 lands; the two former, however, arrive at superior growth in 

 poor sandy soils, the two latter in damp clay-lands. 



The vegetation of Trinidad, like that of all inter- tropical 



