NOTES AND QUERIES. 



407 



geological inferences, improperly so called, have rather provoked merriment than 

 serious attention, ^'liich, combined \nth the habit of assuming no very probable 

 conjectures for demonstrable truths, has rendered Geology somewhat unpopular 

 even among professed men of science; and the term "logic of geology," or some- 

 thing similar, expressive more of ii'onical contempt than anxious expectation, 

 or even the present condition of the science. But, throwing off every hasty 

 habit, and discarding every hasty generahzatiou, the student of geology will 

 truly progress ; for theu*'s is a science happily capable of philosophical inference, 

 and one which will amply repay the study devoted to it. I. A. Davies. — At 

 aU times we give insertion to any sensible remarks, whether they convey informa- 

 tion or pourtray doubts or mis-comprehensions for solution. A wrong im- 

 pression produced on one reflecting mind by a want of full information, or a 

 wrong readui^, or misunderstanding of abstruse facts maybe produced on other 

 minds in a like manner and it is obnously one of the duties of a popular 

 magazine on a special science at all times and on all occasions to set right its 

 liumbler votaries whenever any of tliem are doubtful or take a MTong view. 

 Geologists weU versed in the science would perceive at a glance some erroneous 

 notions mixed up with our con-espondent's not in-acute remarks on geological 

 logic, but these points might not be so palpable to general readers. 



There is no reason why Geology should not become ultimately one of the 

 most logical of all the sciences, of which indeed it is a grand and wonderfid 

 combination, and consequently inherently partakes of all their mathematical 

 and logical properties. But wliile geology is in so thoroughly progressive a 

 state, completely logical deductions should not be expected to be produced from 

 admittedly defective data. Upon insecure foundations no one can properly 

 build up logical conclusions. "We admit, howevei', that much that seems 

 iUogical in the writings of some modern geologists, might have presented a very 

 different aspect by a little care on the part of those authors, and we liave ah-eady 

 referred to this carelessness of diction which tends to stamp oiu' science with a 

 want of logic. This is, however, only apparent and not real. The great doctrines 

 of Geology based on a good ground-work of established facts are ujidoubtedly 

 most logically deduced ; and there is certainly notlmig to prevent every minor 

 detail, so aided as geology must ever be by chemistry, mathematics, natural 

 pliysics, and other exact and deductive sciences, bein^ as exact and definite. It 

 is only just, therefore, to conclude that geology, a science compounded of exact 

 and logical sciences, should be, if properly compounded, an exact and logical 

 whole. 



Now our correspondent, in his own example of reasoning, has gone wrong 

 altogether in liis facts chosen as a basis of attack upon geologists for want of 

 logic. He has first thoroughly mistaken, or is altogether ignorant of the true 

 nature and origin of granite. This rock is only a crystalline condition of rock, 

 and in its crystallized condition may be of any age from older than the Cambrian, 

 or lowermost sedimentary rocks, to the newest of the Tertiaries. He is not 

 secure again in his statement that no rocks dip into it, if we understand his 

 meaning to be that it is totally distinct from any connection with other and 

 sedimentary formations ; for certainly sometimes such sedimentary strata, if 

 they do not plunge into it as a plank into a heap of mud, which from the nature 

 of things is not to be expected, at least they sometimes lose their distinctive 

 stratified characters as they approach a granitic boss, and gradually merge into 

 its crystalline and peculiar mineral characters. 



Again, with respect to the vast periods of time required for the formation of 

 rock-strata, our correspondent is more illogical himself than any of the geo- 

 logists he attacks, for they do carefully take as data those physical phenomena 

 which are going on around them, and they do moreover in their application 

 of those data to past conditions take great care to notice and to observe 



