PRIMEVAL IIOGKS. 173 



deduced the conditions as Daubree liad done and pointed out tlie l)earing of 

 the critical point of water. But the chief appHcation wliich he makes of the 

 results is in the endeavor to account for the great quantit}' of detrital mate- 

 rial in existence. He points out that the degradation of elevations would be 

 more rapidly effected by heated waters than by cold ones, and infers, as I 

 understand him, that hot waters would also ultimately yield a greater quan- 

 tity of detritus than cold waters. The latter of these propositions does not 

 appear to me to follow from the former or from j\lr. Mallet's arguments. 

 It would seem to me certain that the maximum accumulation of clastic 

 material would be more rapidly approached were the water hot, but that this 

 maximum would be a similar quantity whether the water were hot or cold. 

 It is perhaps unnecessary to point out that if the purely igneous super- 

 ficial layer ot flie earth's mass was converted into a crystalline rock resem- 

 bling granite at enormous pressures and at temperatures approximating to 

 500° C. the quantity of water in the fluid' state which was instrumental in 

 the transformation must have been comparatively small, for the great press- 

 ure was due to the fact that most of the water formed a gaseous constituent 

 of the atmosphere. This accords with the views of Scheerer and subsequent 

 investigators, that no great quantity of water is needed to render aqueo- 

 io-neous fusion possible. Sedimentation must, therefore, at this period have 

 been an extremely subordinate phenomenon.^ 



There is thus every reason to suppose that the original massive rocks 

 were granitic in composition and in texture. The fact that eruptive gran- 

 ites were ejected in later times only shows tliat at certain depths beneath 

 the surface the conditions of heat, pressure, and moisture which once pre- 

 vailed upon the surface were repeated. Tliat detritus from the original 

 granite under great pressure and at high temperature may also sometimes 

 be metamorphosed into a material similar to the original granite is cer- 



■ As the temperature s.ink still furtber and oceans be^'au to accumulate, the water must have been 

 bi.'hly chart^ed with mineral matter. It is to this later period that Dr. Hunt, who accepts Dau- 

 brle's exposition of the actiou of the earliest condeused water, ascribes the formation of the Archiean 

 schists as chemical precipitates. In the text I am not concerned with tUe formacion of the crystalline 

 schists, but I wish to state that it appears to me impossible to suppose no crystalline precipitates to 

 have been deposited. I do not doubt that such were formed in a manner nearly or auite identical with 

 that which Dr. Hunt maintains. As appears in a preceding chapter, however, I cannot agree with this 

 brilliant thinker in ascribing nearly all crystalline stratified rocks to this process, uor can I believe 

 that anything like the entire Archivan has been thus produced. 



