1818.1 ON THE FOR\L\TION OF ROCKS. 333 



properly speaking, a vein. Basalt is not stratified, 

 nor is the greatest part of what the Wernerians call 

 the newest iloetz trap stratified ; therefore these rocks 

 cannot be said to contain beds, but only fissures, or 

 splits and cracks, filled up with different substances, 

 Avhich can have no relation with the origin of the rock 

 itself. 



The volcanic islands of the West Indies,' such as 

 Grenada, St. Vincent, St. Lucia, Martiiiiqua, I)o- 

 miniqua, Guadaloupe, Montserrat, Nevis, St. Chris- 

 topher, St. Eustacia, and Saba, have but little basalt 

 exposed to view : and in that resemble active volca- 

 noes, wliere the cinders, scoria, and Other porous 

 rocks, have not had time to wear away, or the rivers 

 to cut canals through their currents of Lava, so as to 

 expose the solid interior Lava to our iexamination. 



In ancient, as in the recent Lava, there is no appear- 

 ance of metallic veins, or othei^ metalliferous substan- 

 ces ; and it indiscriminately covers every class of 

 rocks, not unfrequently even vegetable mould, filling 

 up all the inequalities of the surface over which it 

 runs. This is a Strong mark of difference between 

 the Volcanic and Neptunian origin ; for the Neptuni- 

 an being a deposition from water, by the force of gra- 

 vitation, Avould form a bed of the same thickness upon 

 the whole surface, and leave the inequalities of thesur 

 face the same as before the deposition. 



ORDER III. 



Where the rocks resemble much volcanic rocks, but 

 are deficient in their relative situations. Iiavins: no re- 



Vol. I. 



c c 



