Sienite and Granite. 13 



and the scanty soil that has formed a lodgment in its inequalities, is 

 not of th first rate character. 



Sienite and Granite. 



Sienite is intermediate in its characters between greenstone and gran- 

 ite, although most commonly it is only a variety of granite. Both 

 rocks are little liable to decomposition, and occupy a large porportion 

 of the surface with their naked and rugged projections. Still, the soil 

 found among them, particularly on the granite, is generally of a supe- 

 rior character, probably from the fact that most of it must have been 

 derived from decomposed vegetable and animal matter. Hence it is 

 usually of a dark color and fine texture, and not coarse and sandy 

 like the soil above the granites of Europe, that more easily suffer de- 

 composition. 



Should the preceding cursory remarks be the means of exciting the 

 attention of intelligent agriculturists, to the connexion between rocks 

 and soils, an important object will be attained. I have said enough to 

 show that almost all known varieties of soil exist in Massachusetts. 

 But much improvement remains to be made in our agricultural con- 

 cerns, before the excellencies of our soil are fully developed. It is 

 but a moderate estimate to say, that the general adoption of an en- 

 lightened system of cultivation, would, in a few years, double the pro- 

 duce and the value of our improvable lands. That is to say, such 

 would be the speedy result, if all our farmers were to manage their 

 lands as a few now do. 



USEFUL ROCKS AND MINERALS IN THE STATE. 



I shall next proceed to give an account of those rocks and mineral 

 substances found in the State, which have been, or may be useful in 

 the arts, and are consequently objects of pecuniary importance. Those 

 that are employed for architectural or ornamental purposes, first claim 

 attention ; because the state is peculiarly rich in treasures of this kind. 

 It will be easy to see, by a reference to the Map, how extensive are 

 the formations from which they are derived ; although it must not be 

 concluded that every part of a formation will furnish materials of 

 equal value for economical purposes. 



Granite and Sienite. 

 Much confusion has arisen in the application of these terms. They 



