44 ANNUAL ADDRESS, MDCCCLXXIII. 



over hundreds of square miles, are now or ever have 

 been precipitated in the open ocean from mere chemical 

 solutions. It sometimes happens, indeed, that gradual 

 accumulations of such beds of limestone have attained 

 two or three thousand feet of vertical thickness. By little 

 and little limestone is abstracted from sea water to form 

 parts of animals, which dying in deep, clear water fre- 

 quently produce by their skeletons and shells immense 

 masses of strata of nearly pure limestone, which is con- 

 solidated into rock almost as fast as it is formed." And 

 in a lecture in a Dudley Silurian pit, which I had the 

 honour of hearing, he stated the Silurian limestone to be 

 also the result of marine life agencies. His opinion is 

 therefore as clear as it is clearly stated, and it is shared 

 by other leaders in geological science. There must there- 

 fore be very weighty reasons for such a conclusion, and 

 it is scarcely the province of the amateur geologist to 

 question them. 



My own observations, however, imperfect and immature 

 as they necessarily are, lead me to inquire for additional 

 constructive agency for our mountain limestone. Whilst 

 far from disputing Professor Ramsay's conclusion, I am at 

 a loss to account for the unfossiliferous parts which lime- 

 stone undoubtedly contains. Much of it is crystalline, as 

 is the case with the silica it contains. May not chemical 

 forces similar to those which crystallized the silica have 

 also separated some of the limestone ? Or is the crystal- 

 lization of both a result which took place after the con- 

 solidation of the rock ? And if so, why do we find the 

 silica so perfectly crystallized in a mass of amorphous or 

 subcrystalline limestone, if each molecule of the lime- 

 stone has been drawn together by life agency solely ? We 

 all remember the experiment of forcing carbonic acid gas, 



