79 



In a former Chapter mention was made of many of the mine- 

 rals, both in the limestone beds and the calcareous veins, having 

 more or less rounded or corroded surfaces. It would appear 

 that this phenomenon is more common in the beds than in the 

 veins. Kef erring to the corroded minerals belonging to the 

 veins, Sterry Hunt avers that " this rounding of the angles of 

 certain crystals appears to me to be nothing more than a result 

 of the solvent action of heated watery solutions/' But he holds 

 a different view respecting these bodies in the crystalline lime- 

 stones : they " sometimes occur in small distinct crystals, but 

 more generally in rounded irregular grains, which present a 

 marked contrast to the same minerals occurring in the veins. 

 This rounded form of the minerals in the beds of limestone, is 

 to be carefully distinguished from the rounding of the crystals 

 in the veins. In the latter case the rounding is by no means 

 constant, and is confined to a few species, while in the limestone 

 beds it will be found that a rounded form characterizes alike 

 apatite, and quartz, and such silicates as pyroxene (augite), 

 hornblende, serpentine, and chondrodite " *. In accordance 

 with his view, maintaining the organic origin of " Eozoon 

 Canadense" he declares that the " rounded form 3> which cha- 

 racterizes such silicates, occurring in the beds, has been ( ' demon* 

 strated, in many cases at least, to be due to no such subsequent 

 action, but has been given by the calcareous organic structure, 

 in whose chambers these silicates were originally deposited "f. 

 It will not be expected that we can accept this so-called de- 

 monstration after having shown, with" other evidences to which 

 the merest allusion is only necessary at the present moment, 

 that the " chamber-casts " of c< Eozoon Canadense" when 

 they are not bordered by the " nummuline wall/' are usually 

 coated with flocculite, resulting from the disintegration and 

 waste of their component serpentine, just as the same part 

 in its typical state is the product of corresponding changes in 

 chrysotile and more especially since "we now know," as 

 stated by Sterry Hunt, " that water, aided in some cases by 

 heat, pressure, and the presence of certain widely distributed 

 substances, such as carbonic acid, alkaline carbonates, and 

 sulphides, will dissolve the most insoluble bodies/' And con- 

 sidering that watery solutions of the kind are ever present, 



* Geology of Canada, 1866, p. 190. t Ibid. p. 191. 



