Hunt.] 112 [June 2, 



slightly varied, and he only charges me with asserting that he had 

 " virtually believed " in the transformation of granite or gneiss into 

 limestone, as maintained by Messrs. King and Rowney. lie, however, 

 adds the remark, which serves to show his un familiarity with the 

 literature of the subject, that as regards this supposed change of 

 rocks, he "never knew that any man was ignorant enough, or audacious 

 enough to have suggested " it. 



Prof. Dana then proceeds to deny in an emphatic manner, for him- 

 self, certain opinions which he says I attribute to him and to others: 

 1. " The conversion of almost any silicate into any other"; for proof 

 of which I refer to the table of pseudomorphs given in his Mineral- 

 ogy for 1854, as well as the more complete one cited above; 2, 3, 4. 

 The possibility of converting granite, gneiss or diorite, into limestone; 

 5, G, 7, 8. The j)ossibility of converting granite, granulite, gneiss and 

 diorite, into serpentine; 9, 10. The possibility of converting lime- 

 stone into granite and gneiss. Now these statements of his, in the 

 American Journal for February last, are intended to convey only one 

 impression, namely, that I have falsely charged both himself and 

 others with holding these various transformations. Yet every reader 

 of my address and of my reply to Dana's criticisms thereon knows: 

 1, that I never maintained that Prof. Dana has taught explicitly any 

 one of these rock-transformations, and, 2, that I have ishown by nu- 

 merous citations that each and every one of them has been explicitly 

 taught by eminent writers of the school in question, to which Prof. 

 Dana belonged from 1845 to 1858, and to which, till his late declara- 

 tion to the contrary, I still supposed him to belong. 



As regards Prof. Dana's final assertion, in his notice of my Essays 

 in the American Journal for February last, that, " with the exception 

 of the year 1858, I have never held nor taught that metamorphism 

 is pseudomorphism on a broad scale," he will permit me to refer to 

 the teachings of his Mineralogy in 1854, cited above, and, moreover, 

 to quote his own language in 1858 (Amer. Jour. Science (2) xxv, 

 445), where in discussing the question of metamorphism, Prof. Dana 

 refers to his paper on Pseudomorphism, published in 1845 (ibid., (1) 

 xlviii), and says . . . . '• on page 92 of the same paper meta- 

 phism is spoken of as pseudomorphism on a broad scale." It is clear, 

 by his own showing, that this now forgotten and objectionable doc- 

 trine was not taught by him, as he now seems to say, for the first time 

 in 1858, but was then cited by him with approval, as his teaching 

 thirteen years before. 



