ORE TESTS 85 



serve as bellows. Do not blow in jerky breaths. With a little 

 practice you will be able to produce a steady, hot flame. 



You can use the blowpipe with an alcohol lamp, if you have no gas. 

 Put into the alcohol y io of its volume of turpentine. 



c. After you have heated the pyrite for a minute, smell of it. 

 Can you perceive the odor of burning sulphur? What element 

 must pyrite contain? 



Continue heating the pyrite for several minutes in the blow- 

 pipe flame; then let it cool, and test it with a magnet. Is it 

 attracted? What element, besides sulphur, is present in 

 pyrite? Read 137, text. 



d. Rub some hematite on white paper; what color has its 

 "streak"? 



Heat powdered hematite in the blowpipe flame, as you did 

 pyrite. Is any odor of burning sulphur given off? Is the 

 material that remains magnetic? What metal is present in 

 hematite? 



e. Examine a piece of galena and describe it. Break off 

 some pieces; what shape do they seem to have? 



Heat powdered galena on charcoal in the blowpipe flame, as 

 you did pyrite. Do you get the odor of burning sulphur? 

 Heat the galena steadily for some minutes; what happens? 

 Let the product cool and try to cut it with a pocket knife. 

 What substance is it? What elements are present in galena? 



/. What is the color of the copper ore? Break off a little, 

 powder it, and mix it with an equal volume of 'dry washing 

 soda. Heat the mixture in the blowpipe flame. Cut out the 

 mass on the charcoal, break it up finely, and put it into a white 

 dish. With water wash away the excess of soda, charcoal, and 

 unchanged ore. Do you find any heavy material that looks 

 like copper? 



