97 



TAB. CLI. 



CALX carbonata, echini form is. 

 Echinus-formed Carbonate of Lime. 



Class 2. Earths. Order 1. Homogeneous. 



Gen. 3, Lime. Spec. 5. Carbonate of Lime, 



Div. 2. Imitative. 



1 hat animals are indebted to minerals is very evident, 

 although vegetables may be the instruments by which their 

 nutriment is prepared. We may also say that great part of 

 the mineral world is much indebted to the animal for its 

 present appearance ; for, under certain circumstances, na- 

 ture allows the animal construction to remain long after the 

 animal itself. In this instance, it might have been a doubt 

 whether a construction so complete as this Echinus and its 

 spines could be an infiltration of Carbonate of Lime in place 

 of the case, or rather bone, or the remains of the Carbonate 

 of Lime which existed while the animal possessed it. Its 

 fracture is sufficient to determine it to be Carbonate of 

 Lime, without any other trial; and upon examination it is 

 found to be nearly pure. 



Mr. Hatchett, in his valuable account of the shells and 

 bones of animals., proves the case of a recent Echinus to be 

 bone, as it contains its due proportion of Phosphate of 

 Lime. This is therefore the more curious, as there is no 

 Phosphorus remaining to destroy the crystallized character; 

 the carbonic acid predominating effectually in that parti- 



