8 
LETTER III. 
REMARKS ON RECENT CORALS. ...EXPERIMENTS ON, BY 
ME. HATCHETT. 
Some 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 
