30 PROCHEDINGS OF THE COTTESWOLD CLUB 



information l)y the study of limestones. These roeks are, 

 of course, the marine calcareous deposits in the depths of 

 past oceans, now elevated often high above the level of the 

 sea and altered by molecular changes. In limestone then 

 we may ex[)ect to find what is capable of preservation of 

 the life which lived in the sea of past e[)Ochs. 



Much, of course, has already been done in the study of 

 limestones, but, strange as it may appear, the use of the 

 microscope has been but little a[)plied to this work in 

 anything like a systematic investigation. In fact, com- 

 [)aratively little had been done with this instrument in the 

 study of thin section of limestones till Dr. Sorby, l-.K.S., 

 called attention to the subject in his excellent Presidential 

 Address to the Geological Society in 1879. 



Generally speaking. Geologists have been content with 

 fossils which could be detected without the use of the 

 microscope, and this mostly for the i)urposes of the classifi- 

 cation of the rocks or the study of the structure of fossils. 

 The examination of the limestone has yet to be done, and 

 there is much to be learnt. 



After reading the report on "Deep Sea De[)Osits" by 

 Mr Murray, a member of the "Ghallenger" exj)edilion, it 

 occurred to me that it would be of interest to study 

 microscopically the marine calcareous deposits in past 

 e})Ochs, now represented by limestones, and still further 

 test the teaching of Hutton relative to the depths of the 

 sea ancient and modern. 



In attem[)ting this pa[)er, however, it must be clearly 

 understood that the subject is a vast one, a life's work in 

 fact. I can therefore only now give results so far 

 obtained, namely from Silurian, Carboniferous and Jurassic 

 limestones. 



Commencing with the Silurian system, I have selected 

 the Wenlock Limestone as being perhajis the most 

 interesting calcareous deposit in the Silurian sea. 



