68 The Limestones, and Lime [Feb., 



verhill and Lisbon each contain inexhaustible beds of limestone, 

 and it is an interesting fact, that they lie in one range, running a 

 little east of north. Mica and quartz are the only two minerals 

 which vitiate the rock, and diminish its value for quick-lime. 



In Maine, the occurrence of limestone in the primary rocks is 

 "Well established. The beds hold the same relation to the rocks, 

 as in Massachusetts and New Hampshire, and which have already 

 been noticed in the Green Mountain range. Dr. Jackson, in his 

 geology of Maine, remarks, that many valuable beds of limestone 

 occur in the interior of Maine, particularly in York and Oxford 

 counties, where it alternates with gneiss and mica slate, in beds 

 varying from a few inches to several feet in thickness. They 

 generally rest upon the flanks of granite mountains, though they 

 also occur on the hills and table lands. 



These limestones are considered as of the very best quality, since 

 they are free generally, from imbedded minerals and magnesia. 

 When the limestone contains earthy impurities, they may be 

 riddled out, after being partially slacked with a little water. The 

 impurities are well adapted to agricultural purposes, while the 

 pure lime may be employed for mortar. Limestone of the pri- 

 mary system occurs in the following towns in Maine: — Newfield, 

 Norway, Paris, Buckfield, Winthrop, Hallowell, Whitefield, 

 Brunswick, Phipsburgh, Rumford Falls, Skowhegan Falls, Po- 

 land, Carthage and Bingham. 



The primary limestones, if they exist, are not well described 

 south of New Jersey. They are well known in this state. The 

 beds are a continuation of those of Orange county, and contain 

 the same minerals. Serpentine also accompanies the formation 

 penetrating the limestone in disseminated masses, and occuring also 

 with it as associated beds. 



It is a curious fact that serpentine in Massachusetts, forms by 

 itself extensive beds, independent of limestone, as in Middlefield 

 and Chester, while in the primary system of New York, especially 

 of the northern district, they invariably occur together, frequently 

 penetrate each other or lie side by side. Whenever the serpentine 

 is associated with the limestone, the latter contains magnesia inde- 

 pendent of the masses of serpentine which may be contained in it. 



II. Composition of Limestones. 



We shall now proceed to state the composition of the lime- 

 stones of the primary system. Our principal object in entering 

 somewhat minutely into details in this part of the essay is to in- 

 form our readers what limestones contain magnesia, and what are 

 adapted to agricultural purposes. 



It has been taught that those limestones which are situated 

 near the primary rocks, are more likely to contain magnesia than 

 others: and if our recollection of former doctrines does not fail 



