ART. 29. WHAT IS MATTER? 40 " 30. CONSERVATION OF MATTER 42 " 31. MATTER IS ATOMIC 42 " 32. WHAT IS AN ATOM? 43 " 33. THE ATOMIC THEORY 44 " 34. KINDS OF ATOMS 44 " 35. ELEMENTS OF MATTER 47 " 36. THREE KINDS OF MATTER 47 " 37. MATTER IS GRAVITATIVE 50 " 38. MATTER POSSESSES DENSITY 51 " 39. MATTER POSSESSES ELASTICITY 51 " 40. MATTER POSSESSES INERTIA 52 CHAPTER IV AETHER ART. 42. AETHER IS MATTER 54 " 43. AETHER IS UNIVERSAL 58 " 44. AETHER IS ATOMIC 59 " 45. AETHER IS GRAVITATIVE 64 " 46. AETHER POSSESSES DENSITY 71 " 47. AETHER POSSESSES ELASTICITY 74 " 48. AETHER POSSESSES INERTIA 76 " 49. AETHER IS IMPRESSIBLE 78 " 50. AETHER AND ITS MOTIONS 80 CHAPTER V ENERGY ART. 51. ENERGY 83 " 52. CONSERVATION OF ENERGY 84 " 53. TRANSFORMATION OF ENERGY 86 " 54. POTENTIAL ENERGY 87 " 55. KINETIC ENERGY 89 " 56. ENERGY AND MOTION 91 " 57. CONSERVATION OF MOTION 92 " 58. TRANSFORMATION OF MOTION 93 " 59. MOTION AND WORK 95 CHAPTER VI HEAT, A MODE OF MOTION