X CONTENTS 



27. Air a Necessity of Life . . ... 71 



28. Air in the Soil and in Water . . . . 72 



29. The Composition of the Atmophere . . 75 



30. Oxygen and its Uses ' . .- . . .. .1 78 



31. Nitrogen and its Uses "... .. .. ...... '."'1 8.3 



32. Carbon Dioxide ,. , . . . ... . 81 



33. Respiration. The Necessity for Pure Air . 85 



34. Water is a Liquid . ..... . . . 89 



35. Water can Pass into Some Things .' -. . 91 



36. Solution and its Oddities . " . . . 95 



37. Crystals . ." ... '. .' . . 98 



38. Water for Drinking . - '. ' . . . 100 



39. Water for Cleansing ... ; . ' . 10? 



40. Plants Need Water ' . .-'.-.' -. . 105 



41. Capillarity . . ...;.'. : ,' 106 



42. The Beginning of Plant Life . . . 113 

 4j3. The Testing of Seeds . .' .._^-r''^~\\4 



44. The Proper Planting of Seeds ' .; . . 116 



45. The Needs of the Plant . .. . . .- ' I 118 



45. Birds . . . . . - . . : 120 



47. Wild and Garden Flowers . . . , 122 



48. Trees . . . . . 123 



49. A Queer Plant Yeast , . . .127 



50. Another Queer Kind of Plant The Bacteria 129 



51. Souring and Decay . . 130 



52. Disease and Sanitation . 



53. The Source of All Food .. * '' . 'V 137 



54. The Farm a Workshop . . V . '; 140 



55. Tilling the Soil , . . . . . HI 



56. Irrigation and Drainage of Farms 



57. Gardening .... 14.i 



