MARBLE. 
67 
are referable to the same agency. May not this be the decomposition of a compound of 
sulphur and lime, or the metallic basis of lime, which may exist at different and unknown 
depths ? But I shall leave these theoretical considerations, until I have completed the descrip¬ 
tion of our sulphur springs. I will only add, that it is no objection to the explanation here 
proposed, that sulphur springs occur throughout the whole series of New-York rocks, while 
all the workable deposits of plaster are confined to one rock. 
MARBLE. 
The term Marble should perhaps be strictly confined to those varieties of carbonate of lime, 
whether included under the head of granular or compact limestone, which are susceptible of 
a polish, and some minerals of which carbonate of lime forms the principal ingredient. I 
shall apply it, in the present work, to all those varieties of limestone, or those minerals com¬ 
posed chiefly of carbonate of lime, which admit of being dressed or polished, and are em¬ 
ployed for ornamental building purposes. 
Description. The foliated granular limestone, or crystalline marble, is made up of dis¬ 
tinct angular concretions, with a lower lustre and transparency than calcareous spar. These 
grains are of various sizes, from coarse to very fine. When this granular composition dis¬ 
appears, it becomes the compact limestone, which has a splintery or conchoidal fracture. 
The specific gravity of marble is very variable, ranging from 2.40 to 2.84; the crystalline 
kinds being the most dense. 
Colour various, owing to the admixture of foreign substances. When white, it is more or 
less translucent. 
Composition. When pure, this variety has the same composition as calcareous spar, viz. 
carbonic acid 43.56, and lime 56.44, in 100 parts. But it is seldom found in this state of 
purity; almost always it contains silica, alumina and oxide of iron, the proportions of which 
sometimes reach ten or fifteen per cent. 
Dolomite. The granular marble usually known by this name, differs from the preceding in 
composition, and in some other properties. It effervesces slowly in nitric acid; possesses a 
higher specific gravity than calcareous spar, and is a compound of carbonate of magnesia and 
carbonate of lime in somewhat varying proportions. 
The following constitute the more important localities of marble in the State of New-York. 
Clinton County. In the vicinity of Plattsburgh, there is a great abundance of black 
marble of the compact variety, containing organic remains. There is also a valuable quarry 
of a similar marble in Chazy, near the lake, and nearly opposite to Isle La Motte, and it is 
probably a continuation of the same range. When polished, it has a jet black surface, and is 
of great beauty. 
Columbia County. Mr. Mather gives it as his opinion that beds of marble equal to those 
of Stockbridge and Egremont, exist in Hillsdale and Copake in this county. These beds 
furnish a marble, which, although dolomite, is highly esteemed. 
