556 MINERALOGY 



Agate mortar and pestle. Used to grind minerals to a fine 

 powder, and in the washing of assays for malleable buttons. A 

 fragment of the mineral to be ground is wrapped in paper and 

 broken down to a coarse powder with the hammer on the anvil. A 

 small amount is then placed in the mortar and ground. In testing 

 for solubility, gelatinization, and in fusion with the fluxes all 

 minerals must be very finely ground. 



Magnifying glass. Used to examine small crystals, to search 

 washed slags for malleable buttons, and to examine fragments of 

 minerals after heating to determine their fusibility. 



Magnet. A small bar magnet shaped like a cold-chisel, used 

 in testing the magnetism of minerals and slags. 



Files triangular and flat. Used for testing the hardness of 

 minerals and cleaning coals. 



GLASSWARE 



Dropping Bottle. Used to drop cobalt solution or to drop 

 water in mixing charges for reduction on coal. The ordinary med- 

 icine dropper, Fig. 532, is convenient, 

 or one can be quickly made by fitting 

 a small bottle with a perforated cork 

 through which a glass tube extends 

 to near the bottom of the bottle, which 

 is cut off 2 cm. above the cork. In 

 use the cork is grasped between the 

 thumb and second finger, while the 

 first finger is placed over the open 

 end of the glass tube when the cork 



FIG 532 Dropper an( ^ *ube ^ s withdrawn from the bot- 



tle ; by releasing the pressure' of the 



finger on the top of the tube, the liquid contained will fall 

 slowly out, a drop at a time. 



Test tubes. Used for chemical tests in the wet analysis, for 

 boiling acids, etc. A convenient size 15 mm. in diameter by 15 cm. 

 long. 



Filter funnels. Glass funnels 5 cm. in diameter and cut filter 

 papers 7 cm. in diameter. In use the papers are folded twice, 

 forming a quadrant, one side of which is opened, and the cone thus 

 formed is fitted in the funnel and dampened with water, when it is 

 ready for use. The solution to be filtered is carefully poured into 

 the paper, never filling it more than two thirds full. After the 



