89 [Jackson. 



Margarite of Naxos, according to Dr. J. L. Smith, with the spe- 

 cific gravity 2.80 to 3.09, consists of 



Silica 30.02 



Alumina 49.52 



Lime 10.82 



Oxide of Iron , 1.65 



Magnesia 0.48 



Potash and soda 1.25 



Water 5.55 



99.29 

 Formula R^ *Si+2 Xi^ SI+2 H. 



Chlorotold of Naxos, according to Dr. Smith, with the specific grav- 

 ity 3.52 H. 6, consists of 



Silica 23.20 



Alumina 40.21 



Protoxide iron 27.25 



Water 6.97 



Lime 0.83 



Magnesia 0.95 



99.41 

 Practical trials of the Chester emery, by skilled workmen, have 

 proved that it Is fully equal to the best London prepared emery 

 from Naxos, and In one of the fairest tnals, It was found to excel that 

 emery In the work it performed in grinciing hardened swordblades, In 

 the ratio of twenty to fifteen, and the Chester emery wheel after 

 grinding twenty swords was far from being used up, while never more 

 than fifteen had been ground by the wheels armed with the London 

 emery. This experiment was made by Mr. Ames of Chicopee. 



Those familiar with the working of hard metals, or with cutting and 

 polishing of hard stones, need not be informed that this discovery of 

 emery in our country and State is of vast practical importance. I 

 may however remind you, that at the present time when we are man- 

 ufacturing so many arms of all kinds for the preservation of our coun- 

 try from ruin, and when foreign exchange renders Importation doubly 

 expensive, that an emery mine, situated near our great armories, is a 

 matter of national importance. I may also add, that in case of war 

 with any great European power, the mines of Naxos, our only present 

 means of supply, would be effectually closed to us, and then we should 

 feel that a kind Providence had supplied a great want in our defence 

 and for the maintenance of our independence. 



