434 Forbes — Chemistry of the Primeval Earth. 



hitherto been generally received in Europe, as to lead to the in- 

 ference that Dr. Hunt thus gallantly throws down his glove in 

 order to invite discussion upon the subject. 



After taking the opinion of several well-known geologists and 

 chemists upon the lecture in question, the author of these remarks 

 concludes that in this case, at least, silence does not imply consent, 

 since, without exception, all referred to were at variance with more 

 than one of the views therein put forth. He would therefore have 

 gladly seen the challenge of Dr. Hunt accepted by some one more 

 able than himself ; and, consequently, before entering the lists thinks 

 it proper to explain that he has been induced to do so by Dr. Sterry 

 Hunt's special invitation to " have a friendly fight," which he must 

 confess he was not unwilling to accept,' especially as in a late dis- 

 cussion that gentleman's opinions, when quoted by one of his 

 admirers (in the pages of this Magazine) in opposition to his views, 

 were put forward with a show of authority which opinions as yet 

 neither generally accepted nor confirmed can be entitled to.^ 



In his introduction Dr. Hunt adopts the nebulous hypothesis of 

 the earth's origin, assuming the chemical elements to have all been 

 originally present as intensely heated gases, uncombined, and in a 

 state of " indifi'erence " to one another, which he accounts for by 

 referring to Deville's experiments on the dissociation of certain 

 gaseous compounds at intensely high temperatures. A subsequent 

 lowering of the temperature is then supposed to have brought about 

 the combination of the elements, and afterwards the condensation of 

 their compounds into the shape of an igneous fluid globe. 



So far, Dr. Hunt arrives at the conclusion advanced in the last 

 century by Hutton, the propounder of the plutonic theory of the 

 world's origin, which assumed the world to have been at one time a 

 sphere of molten matter solidified by refrigeration. In considering 

 the results attendant upon the cooling of such a molten sphere, 

 writers, however, differ greatly in opinion ; the majority have 

 supposed the formation of a solid crust of more or less thickness, 

 enclosing a still liquid igneous kernel; more lately some have 

 advocated the existence of a solid central kernel along with a similar 

 external crust, whilst the intermediate space contains still liquid 

 igneous matter ; and, lastly, evidence has been recently brought 

 forward indicating the possibility of a solid, or nearly solid globe. 

 Dr. Hunt insists upon the earth being a globe solid to the core, 

 which had solidified from the centre outwards to the exterior, and 

 further represents the first of these views, hitherto the most generally 

 received and maintained by many of the most able geologists and 



1 In the belief that fair discussion advances science, by developing energetically 

 Iboth sides of the question ; such discussions should however only be indulged in by 

 those who can give and take with equal good grace, without losing temper or 

 deviating from the subject at issue by indulging in recriminations or personalities, 

 such as Dr. Hunt at the close of his lecture alludes to, as having disturbed the social 

 relations of the geologists of the last century, and which unfortunately sometimes 

 creep into discussion even in this enlightened age. 



2 Geol. Mag., Vol. IV. p. 287. The author still agrees with " most geologists " 

 in opposition to the opinions referred to. 



