OPPONENTS AND OBJECTIONS. 201 



species.* If, then, such pseudomorphs exist, it appears to be 

 a fact hitherto unobserved, and our authors should at least 

 have given us some evidence of this remarkable case of pseu- 

 domorphism by which they seek to support their singular 

 hypothesis. 



" I hasten to say, however, that I reject with Scheerer,Delesse 

 and Naumann, a great part of the supposed cases of mineral 

 pseudomorphism, and do not even admit the pseudomorphous 

 origin of serpentine itself, but believe that this, with many 

 other related silicates, has been formed by direct chemical pre- 

 cipitation. This view, which our authors do me the honour to 

 criticise, was set forth by me in 1860 and 1861, f and will be 

 found noticed more in detail in the Geological Report of 

 Canada, for 1866, p. 229. I have there and elsewhere main- 

 tained that ' steatite, serpentine, pyroxene, hornblende, and in 

 many cases garnet, epidote, and other silicated minerals, are 

 formed by a crystallization and molecular re-arrangement of 

 silicates, generated by chemical processes in waters at the 

 earth's surface.'* 



" This view, which at once explains the origin of all these 

 bedded rocks, and the fact that their constituent mineral 

 species, like silica and carbonate of lime, replace the perishable 

 matter of organic forms, is designated by Messrs. King and 

 Eowney ' as so completely destitute of the characters of a 

 scientific hypothesis as to be wholly unworthy of consideration, 

 and they speak of my attempt to maintain this hypothesis as 

 ' a total collapse.' How far this statement is from the truth 

 my readers shall judge. My views as to the origin of serpen- 

 tine and other silicated minerals were set forth by me as above 

 in 1860-1864, before anything was known of the mineralogy of 

 Eozoon, and were forced upon me by my studies of the older 

 crystalline schists of North America. Naumann had already 

 pointed out the necessity of some such hypothesis when he 

 protested against the extravagances of the pseudomorphist 



* Annales des Mines, 5, xvi., 317. 



t Amer. Journ. Science (2), xxix., 284 ; xxxii., 288. 



J Ibid., xxxvii., 266 ; xxxviii., 183. 



