£0<2 ANI5fAL MATTER IN FOSSltSj 



deous chancre; so here, tlie exclusion of the blackening par-* 

 tides from the coralline part of the marble seemed to war- 

 rant the supposition, that the coral had acquired a stony im- 

 pregnation previously to its having become imbedded in the 

 including mass of culcareous matter. Thus two distinct la- 

 pidific processes, occurring perhaps at the distance of many 

 ages, may have been employed in forming the marble of 

 which we are now treating. Any difficulties which appear 

 to be in the way of this supposition will diminish, when it is- 

 Breccias. considered, that in several marbles, indeed in all the breccia 



marbks, this tvvoi'old lapideous impregnation must necessa- 

 rily be admitted. ' These are composed of fragments of va- 

 rious marbles, which, after having been formed in perfect 

 strata, have been broken into small pieces, and have then 

 become agglutinated into a compact mass, by the medium 

 of a fluid, which, from its saturation with the carbonate of 

 lime, has possessed the required lapidi fie power, which 

 it has exerted during its interposition between these detached 

 fragments. 



The marble di- A piece of this marble was suspended in a glass vessel, 

 gested in dilute ' . ... A , . . . , , ..? .. , , 



muriatic acid, containing diluted muriatic acid, and was speexiny dissolved 



No membrane with effervescence. During the decomposition of this piece 

 appeared, f ma rble, not the smallest filament of membranaceous 

 substance became detached; but, on the contrary, the newly 

 forming surface was as perfectly clean and smooth, as if it 

 had been a piece of primitive limestone: the black matter 

 from which the marble derived its colour falling to the bot- 

 Juit an animal torn of the vessel, during the solution of the marble. This 

 charcoal. powder being dried was projected on melted nitre, and im- 



mediately produced deflagration: a circumstance which, 

 with the form of the coral having been visible in the mar- 

 ble, shows the curious fact, that a part of the colouring 

 matter of the marble was an animal charcoal. 

 A discoid eo- ^ corallite of the discoid kind was suspended in muriatic 

 rallite exhibit- acid much diluted, which, by removing the calcareous earth, 

 ar» ma soon exposed the flocculent membranes of the madrepore. . 



But, in this instance, the membraneous flocculi were 

 exceedingly small, hanging but a very little way below the 

 ridge of the coral ; and, on the least agitation of the glass, 

 innumerable minute portions of membranes became de- 

 tached, 



