Serpentinite of the Lizard. 287 



cases are imbedded in tremolite. We have represented in fig. 

 10 two more rods of serpentine, but imbedded in calcite ; and 

 in fig. 11, other four composed of calcite (dissolved out by de- 

 calcification) and imbedded in tremolite. Evidently in all 

 these cases we have different results from chemical changes ; 

 while one of them, just like those represented in figs. 5 and 

 6, unmistakably makes it known that calcite is one of the pro- 

 ducts of these changes. 



Dr. Sterry Hunt has pronounced that we are transmuta- 

 tionists holding " extravagant views." Nevertheless this is no 

 proof that we are wrong. Without going into the various evi- 

 dences which have been adduced in our former papers, we 

 would simply submit that the cases adduced in the present 

 communication are a sufficient answer to the vivacious utter- 

 ances of our esteemed fellow labourer, and that they alone 

 are of more weight in a scientific discussion than all the inge- 

 nious elaborations, devoid as they are of any reliable and tan- 

 gible evidences, which he has brought forward in support of his 

 dogma that serpentine and other mineral silicates (steatite, 

 hornblende, pyroxene), also the calcite associated with them, 

 characterizing the Laurentian ophites of Canada, were "directly 

 deposited as chemical precipitates," — " formed by a crystalli- 

 zation and molecular rearrangement of silicates generated by 

 chemical processes in waters at the earth's surface," and " not 

 by subsequent metamorphism in deeply buried sediments" *. 



* Chemical and Geological Essays, p. 300 ; Geology of Canada, 1866, 

 p. 577 ; Quart. Joum. Geol. Society, vol. xxi. p. 70, &c. If Giimbel advo- 

 cates this dogma, he lays himself open to adverse criticism in his letter, quoted 

 "by Sterry Hunt (C. G.E. p. 305, footnote) : — " I do not maintain a metanior- 

 phic origin for the primitive rocks ; for, although these are certainly much 

 altered, there are no firm and consolidated rocks which are not so." [Is it to 

 be understood, " altered like those forming the Laurentians "?] " They were 

 formed like, for example, the limestones of more recent periods" [what 

 limestones?]: these were once pastes, magmas, or muds; and so were the 

 primitive rocks at the time of their origin ; but during these first ages of the 

 earth the consolidating and crystallizing forces (differing in degree only 

 from those of the present time, and aided by a higher temperature) allowed 

 the magma to assume the form of mineral species, more or less "distinct. 

 If we choose to call this change metamorphism, then the rocks thus formed 

 are metamorphic; but so are the limestones of later periods." This is a 

 strangely inconsistent way of reasoning. The " much altered" condition 

 of a large group of rocks (diorites, gneisses, serpentinites, dolomites, &c.) 

 is illustrated by the formation of " limestones of more recent periods." 

 Why is there no reference to any contemporaneous argillaceous and arena- 

 ceous rocks containing substances convertible into mineral species with 

 forms " more or less distinct " ? Again, excluding such as Carrara marble, 

 Permian and other dolomites (whose metamorphism or methylosis we 

 have always contended for), what other recent limestones have assumed 

 the altered or crj^stalline condition corresponding to that of "the primitive 

 rocks" ? Surelv encrinal and other fossiliferous "limestones of more recent 



