33 
1 proceed to notice a few of the minerals belonging to 
.Earthy Fossils , the fourth and last class, and first of Lime. 
This substance exists in nature in various States of combina¬ 
tion, all of which are appropriated to important purposes in 
the arts. No one however is used more frequently than 
the carbonate . It exists in large quantities over every part 
of the gdobc, and is often the basis of whole districts of coun¬ 
try.* Its forms are so various, that it has received many 
different appellations. Lime stone is used principally in ma¬ 
sonry, and is also applied in the manufacture of gdass and 
smelting of iron ore. By calcination, the carbonic acid is 
expelled. Until this substance was discovered in this 
country, the deficiency Was severely felt. In 1644, the fort 
on Castle Island, (Massachusetts) fell into premature decay, 
as it was built from lime burnt from oyster shells,! a car¬ 
bonate also, but not sufficiently endowed with the property, 
of hardening by exposure to air, which the native mineral 
possesses. Lime is now found of a superior quality in the 
state of Rhode-Island, from which all the adjacent states are 
supplied. It is often met with in other parts. In its com¬ 
pact, hardened forms, combined with clay, silex, and often 
iron, it is used for building-! To this class is to be referred 
the freestones so frequently found in large quantities. Some 
■species of it are apt to peel and crumble by exposure to air 
and water, and particularly by the operation of cold on a 
moist atmosphere, as is the case in England. For the 
building of temples to their gods, and palaces to their kings* 
the Egyptians used granite and porphyry, substances dura¬ 
ble as the earth, and which will still remain, the wreck of 
past ages, after modern architecture shall have crumbled 
into ruins.§ Marl and calcareous slate also belong to this 
species., The one being a carbonate combined with a cer- 
* Such is the case in the south of England. 
f Holmes’ Ame?’ican Annals, vol. 1, p. 331. 
ij: Westminster Bridge is built of Portland stone, a species of 
lime stone, (Kidd, vol. 1, p. 21.) 
§ Vide a paper “ on the application of mineralogical and 
chemical science to the selection of stone for the purposes of du¬ 
rable architecture,” bv Robt. Rakewell. Mease’s Archives, vol. 
2, p. 157. 
D 
