MINERALOGY. 



BY THOMAS T. BOUVK 



In view of erroneous ideas prevalent in the minds of many, a 

 few remarks of a general character concerning minerals may not 

 be out of place. 



It should be understood that mineral bodies are not limited to 

 those of a stony nature, but that they embrace everything of an 

 inorganic character that is found within or at the surface of the 

 earth. This definition therefore includes not only all Rocks, 

 Pebbles, Sands, and Clays, but even Water, and the Gases that 

 form the atmosphere. Temperature alone determines the condi- 

 tion of inorganic bodies so far as relates to their being Solid, Liq- 

 uid, or Gaseous ; and at a low degree Ice is as much a rock as is 

 Granite or any other solid earthy material. Raise the tempera- 

 ture enough and all matter becomes Liquid or Gaseous. No one 

 but admits Quicksilver to be a metal because at the ordinary 

 temperature of the atmosphere it remains a fluid. 



Not an uncommon thing is it to meet persons who think that 

 stones grow like organized beings ; and often this view is supposed 

 by them to be fully demonstrated by the statement that after plow- 

 ing a field and picking out, as they believe, about all the stones 

 in the soil, they find quite as many as they first did when again 

 plowing the same field a few years later. It is difficult sometimes 

 to convince such persons that they are wrong. Of course there is 

 no such thing as inward development of a stone, as is the case 

 with organic life, and there is no possibility of a pebble or other 

 rock mass in the soil adding one atom to its substance. There is 

 often enlargement, where a rock is forming by accretion, as when 

 hot waters containing carbonate of lime deposit it on that already 

 formed, or when mountain rivulets that have taken up iron from 

 decomposing rocks in their course, deposit this from time to time 

 as a bog ore in marshy grounds. So in caverns, waters saturated 

 with carbonate of lime dripping into them from above, form 

 stalactites and stalagmites, slowly constructing the beautiful 

 columns that are seen in the Mammoth, the Luray, and many other 

 caves of our country. 



