NATURE-STUDY LESSONS. 165 



(_/) Their specific gravity. See Lesson XLV, No. 19. 



(g) Their solubility. Frequently it is important to 



note the action of the pulverized mineral in 



hot hydrochloric acid. 



{k) The manner of extracting a particular mineral 



from the earth. 

 (f) Taste. — Some minerals like common salt are 

 soluble in water. These usually have a dis- 

 tinct taste — saline, astringent, bitter, pungent 

 or acid, 

 (J) Odor. — Many minerals on heating give off char- 

 acteristic odors — sulphurous, or that of garlic, 

 or of decaying horse-radish, or of rotten eggs, 

 or of prussic acid. 

 Minerals fall into two great subdivisions : — 

 (a) Metals. 

 {b) Non-metals. 

 All true metals have metallic lustre and are opaque in 

 the thinnest sections. 



The chief metals in Canada are gold, silver, platinum, 

 lead, copper, nickel and iron. 



The chief non-metals are coal, asbestus, mica, clay, 

 petroleum, natural gas, building-stone, arsenic, salt, and 



apatite. 



XLVII.-TEMPERATTJRE. 



Procure the following : — 



{a) Four beakers (tumblers) of water at temperatures 

 of approximately 60° C. (140° F.), 30° C. (86° F.), 10° C. 

 (50° F.) and 0° C. (32° F.), respectively. 



{b) A small quantity of water, say 60 grams (one- 

 fourth of a tea-cup), at boiling point. A much larger 

 quantity, 600 grams (3 tea-cupfuls), at 40° C. (104° F.) 

 and a piece of ice. 



