110 David Forbes — Reply to Dr. T. Sterry Hunt. 



fore the interior had became entirely solid, a view which I have 

 adopted on his authority, and which is diametrically opposed to Dr. 

 Hunt's opinion that the surface of the earth immediately previous 

 to its entire solidification was " a liquid bath of no great depth, sur- 

 rounding the solid nucleus." 



Again, although he finds it convenient to quote Forchammer in 

 reference to some minor points quite beyond the limits of the present 

 discussion, he seems to be quite unaware of the fact that the idea of 

 the saline crust of chlorides, &c., which he ridicules my having 

 adopted, was long before propounded by Forchammer, who made the 

 calculation that the chloride of sodium in such a crust would have 

 been fully sufficient to have clothed the entire sphere with a coating 

 of salt some 10 feet in thickness. 



And yet again when he refers to Sorby's experiments as proving 

 many points in favour of his views, amongst others that quartz can- 

 not be volcanic, i.e., a product of igneous fusion in nature, his deduc- 

 tions are at once entirely put to rout by the few lines from Sorby 

 himself, produced in my last communication to the Chemical News. 



On the other hand, after a careful consideration of the various 

 memoirs of Hopkins, Forchammer, and Sorby, along with a careful 

 repetition of many of their experiments, I cannot discover any one 

 single point inconsistent with the views I have advanced. I am 

 also able to bring much evidence in their favour from the writings 

 of Daubree, Bunsen, Durocher, Phillips, and other men of eminence, 

 whose opinions Dr. Hunt evidently considers of no importance. 



To prove that it is better to stay at home in one's laboratory than 

 to travel wide and far in order to study Nature's operations in the 

 field (as recommended by Sir Charles Lyell and other eminent men). 

 Dr. Hunt quotes Thomas a Kempis, to the effect that " those who 

 make long pilgrimages rarely become saints." What we require, 

 however, is geologists, not saints ; and it is well known that a know- 

 ledge of the world acquired by travel is the best antidote to bigotry 

 or one-sided opinions. 



As I have previously explained, I was induced to enter into this 

 controversy (which I am quite confident will do good to science, 

 by ventilating some obscure points) by the special invitation, 

 conveyed in writing, from Dr. Hunt "to have a friendly fight;" 

 but 1 now find, if I may judge from the style of that gentleman's 

 communications, both to the Geological Magazine and Chemical 

 News, that his idea of scientific discussion consists in an attempt to 

 overwhelm his opponent with sneers and countless accusations of 

 incompetency and ignorance,^ — ignorance of chemistry, of geology, 



* Dr. Hunt does not merely content himself with mere accusations of ignorance, 

 for when disputing my assertion that " reactions of the compounds of magnesia with 

 carbonic acid in an artificially compressed atmosphere of that acid," had long been 

 employed on a large scale, he uses the words " here it becomes difficult to admit 

 the plea of ignorance, which suggests itself for most of Mr. Forbes's previous errors 

 and mis-statements." I may merely add that, since the appearance of Dr. Hunt's 

 communication in tbe Chemical INews of January 17, I have received various com- 

 munications from Chemists and others, connected, or acquainted, with this manufac- 

 ture, not only offering to supply more facts in corroboration of the truth of my 



