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a greater (lei)th, some of those organisms from the bottom of the 

 sea, which, when taken from a depth of about two thousand 

 fathoms, appear to be white and moderately firm, assume a rotten 

 appearance, and become grey ; and at still greater depths they 

 gradually turn into a red clay. The curious feature is this — that 

 it would appear as if this red clay consisted mainly of the remains 

 of organic life. 



Whether there is in the shells of these minute organisms a 

 sufficient portion of aluminous matter to constitute this red 

 clay, when all the chalk is dissolved away, is somewhat 

 disputed between Professor Wyville Thomson and Dr. Carpenter. 

 Professor Wyville Thomson is of opinion that two per cent, of 

 the otherwise calcareous shells is insoluble, while Dr. Cai-penter 

 thinks that the appearance is not due to the presence of clay itself, 

 but rather to the disintegration of the greensand, which itself is 

 due to the decomposition of the fleshy matter, the sarcode of the 

 animals. It has long been known that over various portions of 

 the Chalk area and various limestone districts we have red clays, 

 and in all probability these red clays are in a similar manner due 

 to the solution of the lime — the chalky matter — from the original 

 chalk or limestone, leaving this insoluble portion on the top of the 

 rock. In the same way, it is supposed that at the bottom of the 

 sea there is a current of cold water, not improbably the result of 

 ice melting at the poles, containing a sufiicient quantity of car- 

 bonic acid to dissolve away the lime and leave the insoluble 

 portions at the bottom. No doubt these discoveries would tend to 

 throw some light on the cx>nditions under which our Chalk has 

 been deposited. But what I would call attention to is the desira- 

 bility of making some experiments with our chalk, in order to 

 ascertain by actual investigation what portion remains insoluble 

 when exposed for a length of time to water charged with carbonic 

 acid. I think we have some chemists among our body, and that 

 there would be no difiiculty in carrying out experiments which will 

 be not only of local but general interest. 



Another (juestion to which the attention of the members of the 

 Society miglit well be directed is that of the origin of flint. In 

 certain portions of the sea at the present time there are a vast 

 number of those minute organisms, the diatoms, which have the 

 power of secreting a flinty instead of a calcareous shell from the 

 water of the sea, which contains not only lime, but a certain 

 amount of flint in solution. Sponges have tlie same peculiarity of 



