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?

37. What is said of perpetual motion? Why is it not true of divisibility that it is an essential property of matter? What is said of weight?