OF EDUCATION 7 1 



making distant objects look indistinct. There is a 

 gentle west wind blowing now. 



" We have had a pleasant lesson on a mineral 

 called siderite. This beautiful and interesting min- 

 eral is of a dark golden brown color, with cleavage 

 faces running in three directions. It is a kind of 

 steel ore. Massive siderite has rough surfaces, with 

 the cleavage faces in small pieces. Siderite crystal- 

 lizes in rhombohedrons, but is rarely found crystal- 

 lized. It is composed of three elements, iron, oxygen, 

 and carbon. Forty-eight per cent, of sid'erite is iron, 

 forty-two per cent, is oxygen, and ten per cent, is 

 carbon. Iron is the most useful of all metals, and 

 the most abundant of all elements after oxygen, 

 silicon, and aluminum. It is used for a great many 

 things. Oxygen is the most abundant of all elements. 

 It is an invisible gas, and supports fire, and all ani- 

 mal life. It makes up eighty-nine per cent, of water, 

 and fort)-- five per cent, of the whole crust of the 

 earth. Carbon is the same as charcoal, and the dia- 

 mond is pure crystallized carbon. It is a very use- 

 ful element. The luster of siderite greatly resembles 

 that of feldspar, but it has a little of a metallic luster, 

 besides the pearly. Some very smooth cleavage 

 planes are slightly iridescent. The degree of hard- 

 ness is four, a little more than that of galena, which 

 is about three. The specific gravity is four, about 



