SULPHUB. 183 



out vaults and sewers. Sulphuretted hydrogen burns with 

 a pale blue flame, producing sulphurous anhydride and 

 water, H 2 S+O 3 =H 2 O-f SO 2 . It dissolves in water freely, 

 and the solution is of great service to the analytical 

 chemist as a reagent, for it forms colored sulphides with 

 solutions of many of the metals. This solution does not 

 keep perfectly, sulphur precipitating, and hydrogen escap- 

 ing or uniting with oxygen. 



QUESTIONS. 



233. How does sulphur occur in nature in the mineral kingdom ? How 

 in the vegetable ? How in the animal ? 234. What is said about the forms 

 of sulphur ? What is the meaning of dimorphous ? 235. How can soft sul- 

 phur be made ? Why is it called amorphous ? 236. How are flowers of 

 sulphur made ? 237. What are the properties of sulphur ? 238. What does 

 burning sulphur produce ? 239. How is sulphurous anhydride prepared ? 

 How are sulphites formed ? 240. Explain the bleaching power of sulphur- 

 ous anhydride. 241. What are the properties of sulphuric anhydride? 

 How is it prepared ? What is Nordhausen oil of vitriol ? 242. State in 

 full the process of manufacturing sulphuric acid. 243. Explain the reac- 

 tions by equations. 244. What are the properties of sulphuric acid? 245. 

 What happens when you mix concentrated sulphuric acid with water? 

 246. What remedy should be employed to prevent the corrosive action of 

 sulphuric acid on the skin ? 247. Name some of the uses of sulphuric acid. 

 What is the distinction between neutral and acid salts ? 248. How is sul- 

 phuretted hydrogen best prepared ? What is the equation ? What are its 

 properties ? What is said of its burning ? What of its solution ? 



