EXPERIMENTS IN THE CHEMISTRY. Si 



freshly -cut potato or apple. Blue specks will show the pres- 

 ence of starch. 



96. I. Melt a quantity of sulphur, either the flowers or 

 brimstone, in a test-tube. It is at first thick and dark-colored, 

 but after continued heating becomes thin and dark-colored. 

 Pour it now into water and it will form an elastic gum, which 

 can be moulded into any desired form. 



2. Heat a piece of brimstone in a test-tube. After a little 

 the sulphur will sublime and collect in the upper part of the 

 tube as flowers of sulphur. 



3. Fill a cup with brimstone and melt it with a gentle 

 heat. Set it aside to cool. When a crust has formed on 

 top, break it and pour out the liquid contents. If the cup 

 be broken, the bottom will be found covered with crystals of 

 sulphur. 



1OO. Place in the evolution-flask half an ounce of sulphuret 

 of iron. Cover this with water, and then pour in oil of vitriol 

 through the funnel until the gas comes off freely. It may 

 be passed through a glass of cold water. This solution must 

 be bottled and closely corked. The gas may be tested di- 

 rectly; see page 137. 



1O2. i. Cover a stick of phosphorus with dry, fine-pow- 

 dered charcoal. It will soon ignite. 



2. Put in a vial half an ounce of sulphuric ether and a half- 

 dozen pieces of phosphorus not larger than grains of wheat. 

 Thoroughly shake and then set away. Repeat the shaking 

 often. When the phosphorus is dissolved, pour a little of the 

 solution on the hands, and when briskly rubbed together in a 

 dark place they will glow with a ghostly light. 



3. Pour some of the solution on a lump of loaf-sugar. Drop 

 this in hot water, when the ether will catch fire. 



4. Place in a wine-glass a few crystals of chlorate of potash 

 and a small bit of phosphorus. Fill the glass nearly full of 

 water. By means of a funnel-tube, pour a little oil of vitriol 

 to the bottom of the glass. A violent deflagration will imme- 

 diately take place, and, in a daik room, flashes of green light 

 will be seen. 



119. Cut off three or four inches of magnesium ribbon, and 

 holding one end with a pair of pincers, thrust the ot-bf-r into 



