272 A. B. Sunt — A Vindication of Bacon, Huxleij, and others. 



It will be observed that Lord Kelvin's granite is not necessarily 

 even a plutonic rock. Its original crystals of mica, felspar, quartz, 

 hornblende, and other minerals are brought together by gravitation, 

 and have invariably a basaltic matrix. Ex hypothesi, it can never 

 be otherwise. Now the questions arise whether a granite of this 

 description has ever been seen by any petrologist, and does it 

 accord with the microscopic character of any known granite ? But, 

 granting for the sake of argument the possibility of the formation of 

 such a primeval granite ; to what entirely different origin are we 

 to attribute the numerous non-primeval granites in which gravitation, 

 drifting, and surface consolidation are out of the question, and yet 

 granites of different ages are practically indistinguishable the one 

 from the other ? Lord Kelvin's theory not only assumes that all 

 the granitic minerals crystallized out of the basaltic magma simul- 

 taneously, but that all sank at the same rate, and were therefore all 

 heavier, and equally so, than the residual liquor ; whereas, assuming 

 that the granitic minerals, mica, felspar, and quartz, could crystallize 

 out of a magma largely composed of augite and iron, they would 

 tend to rise rather than sink, and these granitic minerals would have 

 consolidated at the surface instead of the bottom. But, as it is an 

 established fact that the granitic quartzes and felspars consolidated 

 under great pressure, in the presence of water in some form, it is 

 clear that granite was formed in some other way than by a shower 

 of crystalline granules. 



Geologists have hesitated to propound a ' Theory of Granite,' 

 knowing the difficulties ; therefore. Lord Kelvin's theory holds the 

 field. Now, Lord Kelvin's 'Probable Origin of Granite,' and of 

 Basalt, occupies exactly two octavo pages. Within that small space 

 the word ' must' occurs eight times, the word ' probable ' or 'probably ' 

 six times, ' may have ' twice, ' pretty sure ' once, ' almost certainly ' 

 once. Any one of these words or phrases would suffice to cast suspicion 

 on a new theory ; but it is not a case of one, but of eighteen. Such 

 a doubtful ' axiom ' must be founded on not a few fallacies, and here 

 are two of them. Lord Kelvin assumes that because consolidated 

 basalt is heavier than molten basalt, and will therefore sink in its 

 own liquor, every mineral crystallized out of the basaltic liquor will 

 also sink. But as is well known, though some minerals are heavier 

 than the liquor, others are lighter. Secondly, Lord Kelvin overlooks 

 the fact that lava, frozen on the surface of a lava-lake, would often 

 entrap bubbles of expanded gases, and be therefore very much 

 lighter than the main mass of the lava, whether solid or liquid. 

 Some of our cosmogonists would do well to refresh their geology by 

 a reference to Lyell on the subject of pumice. 



As Lord Kelvin's ' Theory of the Age of the Earth ' seems based 

 on the false hypothesis that consolidated basalt and crystallized 

 minerals must necessarily sink in liquid lava, the failure of the 

 hypothesis, or underprop, involves the collapse of the theory. 

 Pengelly's assimilation of the Baconian teaching was much as 

 follows. Every theory is based on many facts, or supposed facts. 

 If a single one of these supposed facts is disproved the whole theory 



