1817.] GEOLOGY OF THE WEST INDIES. 143 



very fine cinders fell on the decks of vessels three or 

 four hundred miles to windward, supposed to have been 

 carried by a counter current of air, in the upper regions 

 of the atmosphere. 



Dominica is in general composed of cinders, with rolled 

 and detached pieces of lava, pumice, Sec. disseminated so 

 as to form a kind of pudding. stone, containing five times 

 more of the cement than of the detaclied pieces. Where 

 compact lava appears, it is in masses, seldom in currents, 

 and generally covering the cinders, and is also covered 

 by them. 



The soufriere is in the bottom of a bay, at the south 

 end of the island, and has all the appearance of being 

 the remains of an ancient crater: it is extensive, and fur- 

 nishes at times both sulphur and alum, the quantity of 

 alum rocks being considerable. There are other fume- 

 rols in the interior of the island, which might furnish 

 alum and sulphur. 



On the top of the mountain, as you cross the island, 

 there is a lake, having all the appearance of being an old 

 crater, about which the quantity of loose stones is greater, 

 and of cinders less, than on the coast. 



A bed of coral and madrepore limestone, with shells, 

 lies horizontally on a bed of cinders, about two or three 

 hundred feet above the level of the sea, at Rousseau, and is 

 covered with cinders to a considerable height. 



Basseterre in Giiadaloupe, On landing at St. Rose, 

 at the north end, the red clay occurs as at Lamentine in 

 Martinico, and is the result of the decomposition of ihc 

 same compact blue basaltic rock, which appears to prevail 

 over all the low country, dividing Grandterre from Basse- 



