29. What is said of the ductility of melted glass? What of the change of position of particles in making plates and wires of metals? What of welding? What is said of compressibility? What of the incompressiblity of liquids?
30. What influence has heat on the bulk of liquids? Illustrate by the thermometer. What is said of the compressibility of gases? How does elasticity operate in the case of the India-rubber ball?
31. Give the illustration in regard to jumping. State the experiment with the ivory ball. What is said of the movements of particles on each other in elastic substances? What of the degrees of elasticity in different substances?
32. What is the definition of elasticity? What is said of the usefulness of the variety of properties in matter?
CHAPTER III.
33. What is meant by extension as a property of matter? Illustrate the fact that it is an essential quality. What is said of it in reference to air?
34. Does matter ever penetrate matter? Give the illustration represented in Fig. 6. Give that represented in Fig. 7.
35. State the arrangement of the diving-bell. Give the comparison between bullets and needles in relation to penetration. What is said of solution? What of odors?
36. What is the property of matter called inertia? Give illustrations of it. Illustrate the fact that matter has no power to stop its own motion. What is the reason that the popular notion is that matter is more inclined to rest than to motion?