[ 17 ] 
Having dwelt a little upon the fubjedl of bafaltine orga- 
nization, I fliall beg leave to add a few remarks concerning 
the origin of thefe bodies. The fyftematicalmineralogifts, 
in general, affignthe fame common origin to moil lapide- 
ous folids, which they fuppofe to be generated by depoh- 
tion from an aqueous fluid. In whatever manner, there- 
fore, the prifmatic bodies in queftion are claffed upon fuch 
a principle, no adequate idea can thence be afcertained 
concerning their origin, which feems manifeftly difierent. 
For furely the ftru6ture and other phaenomena of thefe bo- 
dies fufiiciently prove them to be cryflallizations or con- 
cretions of a particular kind, and generated immediately 
from an igneous fluid: for they are not only peculiar to vul- 
canic tra6ts of country ; but differ, in every refpe6t, from 
common cryflals produced from an aqueous fluid. Every 
one knows, that the latter are formed Jlratum fuper Jlra- 
tum^ by a flow and fucceflive depofition and juxta-poH- 
tion of parts, as hath been proved fatisfadtorily by cap^ 
PELER, LiNN^us, and other writers on this fubjedt. The 
fame mode of generation is more particularly explained 
by STENO, in his excellent treatife De folido intra folidum 
naturaliter contento. But this mode does not feem at all 
reconcileable with the bafaltine cryflallizations in quef- 
tion, For however thefe bodies may vary in their tex- 
ture, none of them, notwithflanding, afford the lead: in- 
dication of an origin common to other cryflals ; but feem 
rather the effedls of fome intrinfic principle of organiza- 
tion, by which tiiey appear to have been produced fimul- 
VoL, LXV. D taneoufly, 
