ANIMAL MATTER IN FOSSILS. 



219 



seen, that the colour does not exist in the intermediate cal- 

 careous matter, or in that which has been introduced into 

 the cavities of the tubes, but in the substance of the coral, 

 forming the sides of the tubes. 



It aopears, from the experiments of Mr. Hatcbett, that This some un. 

 the colouring matter of the organ-pipe coral is similar to known modifi- 

 tlmt of the red coral, (gorgonia nob'disj being some unknown mal matter< 

 modification of animal matter. The red colour of both 

 these substances having been gradually destroyed, during 

 the action of the diluted nitric acid, as the solution of. the 

 calcareous substance advanced ; and could not afterward by 

 any means be restored : nor could any colouring principle 

 whatever be detected by the reagents usually employed*. 



We also learn from the Count de Marsilli, that by digest- solution in 

 ing red coral, with or without its membranaceous tunic, in milk, 

 milk, over a slow tire, the colouring matter was dissolved 

 by the milk, which became thereby of a pink colour; while 

 the coral became first of a saffron, then of an ash colour, 

 and sit last of a livid white. The same etlects resulted from 

 its digestion in heated wax. A similar deprivation of colour m jj ot wax 

 is also found to take place in those species of coral, which, 

 having been broken, have fallen into, and have remained for ancl in mu( j f 

 some time in the mud at the bottom of the seaf. the sea. 



As the colouring matter of these corals is capable of be- Thus most f 

 ing thus removed by digestion, it is not to be wondered at, sils deprived of 

 that, in general,, in the fossil specimens, which must, in most lt * 

 instances, have been exposed to long continued maceration 

 in water, little or none of the original colour remains. 



From the weight and other physical characters, as well as Separate fossils 

 from exposure to chemical agents, I found, that every fossil too siliceous 

 of this species in my collection, not imbedded in stone, con- examination 

 tained too much siliceous matter, to admit, by the agency 

 of an acid, an examination into the change, which had taken 

 place in the original constituent parts of the coral. 



Indeed, considering that in the experiments of Mr Hat- 

 chett even the recent tubipore lost its colour, and only de- 



* Philosophical Transactions, for 1R00. 



f Histoire Physique dc la Mer, par Louis Ferdinand C«mte de Mar- 

 aUJi. 



monstrated 



