46. Explain the cementing of glass. What is said of the adhesion of pieces of India-rubber? Describe and explain the experiment with bullets and with balls of lead. How may silver and gold be made to adhere to iron? What is said of the adhesion of tin and lead? What of the adhesion of panes of glass?
47. Upon what does the strength of adhesion depend? Illustrate the agency of heat in promoting adhesion. Give familiar examples of attraction between solids and liquids. Explain the experiment represented in Fig. 15.
48. What is said of stems in stagnant water? Explain Figs. 16, 17, and 18.
49. Explain Fig. 19. Explain the rise of fluids in tubes by Fig. 20.
50. What is meant by capillary attraction? Give familiar examples of the rising of liquids in interstices.
51. Describe and explain the process of getting out millstones. How does a blotter differ from writing-paper?
CHAPTER V.
51. What is the attraction of cohesion? Give examples of attraction between masses or portions of matter.
52. Explain the falling of a stone to the ground. Illustrate the fact that attraction is mutual. Give the illustration of the ship and boat in full.