METAMOEPHOSIS OE SOME SEDIMENTAEY EOCKS. 355 



only in the school, but in the play -ground, and on the streets ; and 

 the third is that, our newspaper and other writers should abstain 

 from the attempt to add new force to theEuglish tongue by improv- 

 ing the language of Shakespeare, Bacon, Dryden, and Addison. It 

 is true that these are antiquated names ; and it may be that some 

 among us rather know them by the hearing of the ear than the sight 

 of their works : still, weak though it may seem, and — to cull once 

 more, for the sake of illustration, one of the choicest phrases of 

 Canadian letters, — " old fogyish" though it may appear, I cannot get 

 rid of the impression, that those men understood English fully as well 

 as any American or Canadian author, and that, though they never 

 wrote slang, no one either on this side of the Atlantic, or on the 

 other, has written, or is likely to write, either with augmented force, 

 or greater clearness. 



ON THE ORIGIN AND METAMORPHOSIS OF SOME 



SEDIMENTARY ROCKS. 



BY T. STERRY HUNT, 



OF THE GEOLOGICAL SUBVET OF CANADA. 



The progress of Geological investigation has shown that many masses 

 formerly regarded as primitive and even as hypogene rocks, belong to 

 formations, which in other parts of their geographical distribution 

 appear in the form of sedimentary strata, destitute of crystalline cha- 

 racter, and distinguished by their organic remains as pertaining to 

 various geological epochs. Thus the researches of Sir "William Logan 

 have shown conclusively that the serpentines, talcs, diallages and 

 pyroxenites of the Green Mountains are portions of altered Silurian 

 Strata, and I have already suggested that these rocks have been formed 

 by the metamorphosis of certain beds of silicious and 'ferruginous 

 dolomites and magnesites which occur in the Quebec division of the 

 Hudson River Group, and are found in its unaltered portions inter- 

 stratified with pure fossiliferous limestones, sandstones, and graptolitic 

 shales. 



Dolomites have, until recently, been regarded for the most part as 

 altered rocks, and the mode of their formation is but little understood. 

 When carbonated waters, containing lime and magnesia in solution, are 



