EXERCISE PAGE 



33. What are some of the properties of carbon dioxide ? 43 



34. Can the green coloring matter be removed from leaves ? . 44 



35. Is there a food material in the leaf, and does it have any relation to chlorophyll ? 40 



-36. In what part of the leaf is the chlorophyll ? 47 



37. What is the nature and use of the outer covering of the leaf ? 48 



38. Is there a waste product given off during food manufacture ? 49 



39. What is the nature of the gas given off during chlorophyll work ? 51 



40. How does a dependent plant live ? 52 



41. What is the nature of the yeast plant ? 53 



42. What effect has heat upon the yeast plant and fermentation ? 54 



43. How do bacteria act on milk, and how may milk be preserved from such action ? 55 



44. What changes in volume take place when water freezes ? 58 



45. What happens when water boils, and at what temperature does this take place ? 60 



46. How is water distilled, and how may dissolved solids be separated from water ? 62 



47. What effect has evaporation upon temperature ? 63 



48. How rapidly does water evaporate in the classroom ? 64 



48 A. Does ice evaporate ? 65 



49. How rapidly does water evaporate from a plant ? 66 



49 A. Does water evaporate from a plant ? 68 



50. How does a siphon work ? 69 



51. How does a lift pump work ? 70 



51 A. How does a pump operate ? 72 



52. Is the lateral pressure in water different from the pressure downward or upward ? 73 



53. How can water be used in finding the volume of an irregular solid ? 75 



54. What is the lifting effect of water upon an object immersed in it ? 76 



55. Why do objects float in water ? 78 



56. What effect does Lake Michigan have upon the temperature of places near it ? 80 



57. What is the effect of Lake Michigan upon the surrounding country during cold winter weather ? 81 



58. Is there a difference in the rates at which soil and water change in temperature ? 82 



59. What are the principal characteristics of harbors and waterways ? 83 



60. What is the local importance of water transportation ? 84 



61. What is the relation between water supply and disease ? 85 



61 A. What is the significance of the local death rate from typhoid ? 86 



61 B. What is the character of the local water supply ? 87 



62. How is sewage disposed of in your community ? , 88 



63. How are pulleys used as machines, and what are the advantages of different systems of pulley 



arrangement ? 89 



64. How to measure the work done by the force applied in a pulley system in raising a known 



weight a given distance 91 



65. How much work is done upon the weight (work out) in Exercise 63 ? 93 



66. What is the efficiency of a pulley system ? 94 



67. Can one kind of energy be changed into another kind ? 95 



68. What is the principle of the steam engine ? 96 



69. What is the nature of the particles which make up the soil ? 97 



69 A. What is the character of that part of the soil in which no particles can be seen with the 



unaided eye ? 98 



70. How much water may be held by soil ? 99 



70 A. What is the water-retaining capacity of different kinds of soil ? 101 



71. Is there any soluble material in the soil ? 102 



72. What is the amount of organic matter in soils ? 103 



73. How are soils formed ? 104 



74. How does erosion affect soils ? 105 



[vi] 



