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LETTER III. 



REMARKS ON RECENT CORALS., ..EXPERIMENTS ON, BY 



MR. HATCHETT. 



OOME are of opinion, that whilst contemplating the nature, and 

 examining the constituent parts, of those substances which have un- 

 dergone an almost total change in their composition, it is unnecessary 

 to take into consideration, either the circumstances under which they 

 previously existed, or the principles which entered into their original 

 constitution. Not entertaining this opinion, but considering that 

 many may feel themselves highly interested by marking the progress 

 of the change of organized bodies, into substances possessing the 

 properties of a mineral, greater freedom will be indulged in, whilst 

 selecting the various topics, the discussion of which is to fill the fol- 

 lowing pages. 



To form even a probable conjecture, respecting the nature of the 

 changes, which will be the chief objects of our investigations, it 

 appears that the nature of the substances which have undergone the 

 change must first be known ; their constituent principles will therefore 

 be particularized. Since these changes may also be even influenced 

 by the peculiar habits and economy of the living animal, these will 

 also be occasionally adverted to. Thus, in the present instance, the 

 chemical examination of the recent coral, and an inquiry into the 

 properties possessed by the animal which inhabited it, will be likely 

 to yield us considerable aid, whilst determining the changes which 

 have taken place in the fossil coraL 



So great is the resemblance which corals bear to vegetables as to have 

 long occasioned, as has been already observed, their being considered 



