ANIMAL MATtER IN FOSSILS. 22l 



the mass, were previous to the perfecting of the lapidifying 



process. 



On subjecting this marble to the action of diluted nitrous Nitrons add 

 . . •' & . , ... . detected oxide 



acid, its decomposition took place very speedily. A consi- of u<tlij 



derable quantity of carbonic acid gas was separated, the 

 calcareous part was dissolved, and a red substance, an oxide 

 of iron, gradually sunk to the bottom. While the decom- 

 position was proceeding, a substance was detected, the pre- 

 sence of which, at least in so obvious a state, was not expect- 

 ed. As the separation of the other parts took place, ragged and £xp<*ed a 

 ilocculent pieces of apparently a membraneous substance 

 were left, adhering to those parts where the coralline sub- 

 stance had been observable. These, on the least agitation 

 of the fluid, were seen to wave to and fro, and on the motion 

 being increased foil off, and soon reached the bottom of the 

 vessel from the weight of the solid matters which were at- 

 tached to them. 



In the specimens of marble from Kilkenny, the remains Marble fiora 

 of a coral of this kind, but of a larger species, are very evi- ' enny " 

 dent. The ground of the marble is of a deep black, but 

 the part of the marble possessed by the coral is of a very 

 lights gray. In fineness of grain and in susceptibility of 

 polish it appears to equal any marble. From this circum- 

 stance, and from the considerable difference in the colour of 

 the madrepore and of its matrix, the structure of the for- 

 mer becomes very conspicuous, and the astonishing labours 

 of its original inhabitant are very easily traced. In one part, 

 the converging perpendicular plates, displayed by a hori- 

 zontal section of the madrepore, are discovered ; while in 

 another part a longitudinal section has not only shown nu- 

 merous horizontal plates; but also yields a fair view of the 

 beautiful reticular texture of the coral, resulting from the 

 frequent intersections of the perpendicular by the transverse 

 lamellae. 



The very considerable difference of colour in the ground Appears to 



of this marble and in the animal part is particularly deserv- haveun er " . 



1 * * gone two pawl- 



ing of attention. As in the former specimen the regular fymg pro- 



ditfusion of colour through the whole mass appeared to ^ esse "" 

 authorize the conjecture, that the colouring matter was in- 

 troduced previous to the coral having undergone its lapi- 



deous 



