330 QUESTIONS. 



zinc ? Give the names and composition of the three vitriols. How 

 does a sulphate differ from a sulphuret? How are these three sul- 

 phates produced from the sulphurets of the same metals? What is- 

 copperas ? What are its uses ? What is said of sulphate of lead ? 



37. What is the composition of gypsum ? What are its properties? 

 What is said of some of its forms ? What is anhydrous gypsum ? 

 What is said of the gypsum found in the Mammoth Cave of Ken- 

 tucky ? State the case related by Prof. Hitchcock, and the mode of 

 detecting the error indicated. 



38. What is said of the sulphates of magnesia and soda? What 

 of the sulphate of baryta ? What of sulphuric and sulphurous acids ? 

 What of sulphureted hydrogen ? 



CHAPTER V. 



39. What are native metals ? To what is the term ores usually ap- 

 plied ? In what different senses is it used ? What is said of the po- 

 sitions and associations of ores ? 



40. Illustrate the simplest method of obtaining metals from ores. 

 Illustrate the other method mentioned. What is the gangue of an 

 ore? What is the process termed washing? Illustrate the operation 

 of 'fluxes. What are the most common ores of iron ? What is said 

 of them as colorers of rocks and soil ? 



41. What is said of meteoric iron? What of magnetic iron ore? 

 What of hematite ? What of brown iron ore ? 



42. What of chromic iron ? What of carbonate of iron ? Under 

 what circumstances is native copper found ? What is said of finding 

 silver with it ? Where are famous copper mines ? What is said of 

 the copper region of Lake Superior? 



43. How was the copper produced in that region ? What is said 

 of the oxyds of copper? How many carbonates of copper are there? 

 What is said of the one called malachite ? What of the silicate of 

 copper? What of native lead ? What is red lead? What white? 

 What chrome yellow ? What is said of tin and its ores ? 



44. What is said of zinc and its ores ? What of antimony and its 

 compounds ? What of the ores of cobalt ? What of nickel and its 

 ores? What of bismuth and its compounds? 



45. What is said of the ores of manganese ? What are the proper- 

 ties of mercury? What is related of its discovery? Why is it called 

 quicksilver ? How is its purity estimated by the miners ? What are 

 its uses ? 



46. In what various conditions and combinations is silver found ? 

 In what states is gold found ? What is the only compound that has 

 yet been met with ? How is gold distinguished from iron and copper 



