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 . ... . - :' 78 



31. Nitrogen and its Uses '.' .-/:..: Op;. ^ . 80 



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 . '. r ' -91 



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



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



38. Water for Drinking . : . . . . 100 



39. Water for Cleansing . . . " . ' -. 102 



40. Plants Need Water . . .. . : . 105 



41. Capillarity . . . . . ... 106 



42. The Beginning of Plant Life . : > - ' .113 

 4(3. The Testing of Seeds . . .: ^-. . 114 



44. The Proper Planting of Seeds ~ . '% ' '. 116 



45. The Needs of the Plant i| '. / , - ' ., : -'. 118 



46. Birds . . . ' / .i . ; . ' '.. ; 'J'. 120 



47. Wild and Garden Flowers . . . ' \ 122 



48. Trees . . ' .' V ' ". ,'. : \'\ ''^. 123 



49. A Queer Plant Yeast . . \\& "\ 127 



50. Another Queer Kind of Plant The Bacteria 129 



51. Souring and Decay . V . - . | . ". 130 



52. Disease and Sanitation ^' , . . '/.f .'. 133 



53. The Source of All Food - .-^ . ... ' ; . :. 137 



54. The Farm a Workshop .1 ; " ,.:;: I; , . 140 



55. Tilling the Soil . . . . ' ^ .141 



56. Irrigation and Drainage of Farms , . '. . 144 



57. Gardening . .-* '.'... : ?-*!. 1 .- '1 .*.'. 145 



