Mr. Watt’s Observations 
304 
instances of petrifactions found in basalt, and, as a counterpoise 
to that observation, the equally numerous instances in which 
the heat emanating from it appears to have indurated strata, 
and coaked beds of coal. One remark may be stated here with 
propriety, as it arises immediately from the experiment which 
has occasioned these observations. In the ultimate result of 
that experiment, the arrangement of the molecules was much 
more perfect than in the original rock. It might be supposed, 
that a longer continuance of the suitable temperature was 
afforded it. This, however, could not be, for the mass was only 
a few feet long, and a few inches thick ; the fire was only 
maintained a day ; and the whole was cooled in a week. But 
the hill of solid basalt, from which the substance operated upon 
was taken, is several miles long, and several hundred feet high ; 
and, supposing it to have been irrupted in a state of igneous 
fusion, it must have required months, nay years, for its refri- 
geration. How then comes it, that the process of crystallization 
is so little advanced ? How comes the confusion of its texture 
to indicate the very reverse of the tranquillity and perfection of 
arrangement, which may be fairly assumed as necessarily at- 
tending the extremely gradual changes of so immense a mass ? 
This objection admits of being obviated, upon the supposition 
that, in the process of melting, the molecules of the basalt were 
decomposed ; and that the new ones generated were more dis- 
posed to crystallize than those whose place they supplied. This 
explanation is in some degree justified, by the total disappear- 
ance of the minute feldspars and hornblende of the basalt; 
instead of wh : ch, the regenerated stone contains thin laminae of 
crystals, which are probably augites. 
I cannot leave this subject without noticing some particulars, 
