APPENDIX. 105 



evidently thinks supports his belief, but which, as will be learnt 

 from a perusal of Chapter XV., I am totally opposed to. To quote 

 his words : " I repeat that the Permian magnesian limestone 

 was not, as used to be suppose^ formed in the sea, but in an 

 inland salt lake, under such circumstances that carbonates of lime 

 and magnesia were deposited simultaneously, probably by con- 

 centration of solutions due to evaporation. In an open sea lime 

 and magnesia only exist in solution in very small quantities ; and 

 limestone rocks there are formed (as in coral reefs) by organic 

 agency." If, as seems to be meant by the last sentence, lime 

 and magnesia are unlikely to be precipitated in an open sea (a 

 view I quite agree with not, however, because salts formed 

 of these bases are in small quantities, which statement is a 

 slip of some kind), it is to be apprehended that there is little 

 chance of their being deposited in an inland salt lake, consider- 

 ing that Dr. Ramsay has not been able to point out a single 

 instance of the kind. 



" In some of the lower strata of the magnesian limestone, 

 when weathered, it is observable that they consist of many 

 curious thin layers, bent into a number of very small con- 

 volutions, approximately fitting into each other, like sheets of 

 paper crumpled together. These dolomitic layers convey the 

 impression that they are somewhat tufaceous in character, as if 

 the layers, which are unfossiliferous, had been deposited from 

 solutions. In other parts of the district, along the coast of 

 Durham, large tracts of the limestone consist of vast numbers 

 of ball-shaped agglutinated masses, large and small ; and I have 

 observed in limestone caverns, in pools of water surcharged with 

 bicarbonate of lime, that sometimes precipitation takes place on 

 a small scale, producing similar nodular bodies. It is notable 

 also that, when broken in two, many of the balls are seen 

 to have a radiated structure ; that is to say, from the centre 

 rudely crystalline -looking bodies, all united, radiate to the cir- 

 cumference. In other places we find numerous bodies radiating 

 in a series of rays that gradually widen from the centre, and are 

 unconnected at their outer ends, which reminds the spectator of 

 radiating corals. There is, however, nothing organic about 

 them ; and I do not doubt that they owe their growth to some 

 kind of crystalline action going on at the time that the limestone 

 was being formed." 



