IN POPULAR CHEMISTRY. 



93 



entirely regulated by tenacity, iron would occupy the first place, 

 whereas, on account of its hardness, it is the least malleable of 

 metals in ordinary use ; while gold, occupying an intermediate 

 position with respect to tenacity, is the most malleable, which 

 appears surprising to those who are only acquainted with gold 

 in its ordinary forms of coin and ornament, in which it is 

 hardened and rendered much less malleable by the presence of 

 copper and silver. 



I. Relative Malleability of the Metals. 



1. Gold. 4. Tin. 



2. Silver. 5. Platinum. 



3. Copper. 6. Lead. 



TL. Relative Tenacity of the Metale. 



7. Zinc. 



8. Iron. 



1. Gold. 



2. Silver. 



3. Platinum. 



4. Iron. 



III. Relative Ductility of the Metal*. 

 5. Copper. 



6. Palladium. 



7. Aluminum. 



8. Zinc. 



0. Tin. 



10. Lead. 



BLOXAM. 



2. WJiat is the cause of the chanf/iitfs color often seen in 

 thf scum on standing ivater? 



(See " Interference of Light, 1 ' Popular Physics, p. 220.) 

 The thin pellicles of iron-rust on standing H 8 O produce a 

 beautiful iridescent appearance, the color changing with the 

 thickness of the oxide. A soap-bubble exhibits in the same way 

 a play of variegated colors according to the thickness of the 

 film in different parts. 



3. How can the spectra of the metals be obtained ? 



(See Astronomy, p. 285.) 



By looking through a prism at a flame containing minute 

 portions of the volatilized metal, and no solid particles of C. 



4. Ought cannon, car-axles, etc., to be nsed until they 

 break or wear out ? 



