XIII.] ORIGIN OF CRYSTALLINE ROCKS. 325 



alteration of rocks." It will, however, be noticed, that his name 

 has been quoted by Delesse with those of Bischof, Blum, and oth- 

 ers as a disciple of this school, and it has never before been ques- 

 tioned that Haidinger was the first, if not to suggest, to clearly set 

 forth, the theory of the supposed conversion of limestone into 

 dolomite by the action of magnesian solutions, aided by heat and 

 pressure, a theory which I have elsewhere refuted. (Bischof, 

 Chem. Geol., III. 155, 158 ; Zirkel, Petrographie, I. 246 ; Liebig 

 and Kopp, Jahresbericht, 1847 - 48, 1289 ; and American Journal 

 of Science (2), XXVIII. 376). 



Metamorphosis of dolomite to serpentine : This change is main- 

 tained by G. Kose (Bischof, Chem. Geol., II. 423), and by Dana 

 (American Journal of Science (3), III. 89). 



Metamorphosis of granite, granulite, and eclogite directly into ser- 

 pentine, chlorite, and talc : These transmutations are maintained 

 by Miiller, and adopted by Bischof. (Chem. Geol., II. 424, 434.) 



Metamorphosis of limestone to granite or gneiss : This is taught 

 by Blum and Volger. (Chem. Geol., II. 186 ; III. 431.) 



Having thus given the authorities for the examples cited in my 

 address, I may notice some further illustrations of the doctrine 

 from the pages of Bischof s work already quoted. Metamorphosis 

 of diorite, hornblende-rock, and labradorite to serpentine ; G. Rose, 

 Breithaupt, Von Rath (II. 417, 418) : diorite and hornblende-slate 

 to talc-slate and chlorite-slate ; G. Rose (III. 312) : mica-slate to 

 talc-slate and steatite, and mica to serpentine, steatite, and talc ; 

 Blum, C. Gmelin (II. 405, 468) : quartz-rock to steatite ; Blum (II. 

 468). 



[That the extravagant views of the transmutationists, as set forth 

 in the preceding pages, though now denied by Professor Dana, are 

 still maintained by others, is well shown by two recent publica- 

 tions. In one of these, just referred to, Messrs. King and Rowney 

 have gone even further than their predecessors. Not content with 

 teaching the conversion of feldspar, quartz, hornblende, pyroxene, 

 and chondrodite into calcite, they imagine that serpentine, which, 

 according to Dana and others, results in all cases from the alteration 

 of silicated or carbonated species, may itself become the subject of 

 epigenic change, and be converted into calcite. The ophicalce 

 rocks, which are mixtures of serpentine and carbonate of lime, 

 have, according to King and Rowney, been formed in this manner 

 from serpentine ; and they further imagine this process to have been 

 so guided as to leave the unchanged portions of the serpentine with 



