CONTENTS xi 



CHAPTER VII 



INVESTIGATION OF THE COMPOSITION OF VARIOUS 

 KINDS OF MATTER 



PAGE 



75. The separation of a complex body into different kinds of 



matter by a difference in degree of solubility in water . 116 



76. The separation of a complex body into two different kinds of 



matter by a difference of boiling-point . . . .117 

 77 Chemical changes : changes observable when silver nitrate is 



maintained at a high temperature 118 



78. Changes observable when silver iodate is maintained at a high 



temperature 119 



79. Modification produced when silver nitrate is heated within a 



closed tube 120 



80. Decomposition takes place when silver nitrate or similar 



bodies, either liquefied or in solution, form part of an elec- 

 tric circuit 122 



81. The quantity of a given kind of matter, liberated under the 



same electric conditions, is independent of the kind of 

 matter associated with it, while the quantities of different 

 kinds of matter liberated under the same electric conditions 

 have a fixed invariable ratio to one another . . . 123 



82. Decomposition of a body by close contact with another. Forma- 



tion of new kinds of matter when two bodies re-act chemi- 

 cally 124 



83. Chemical combination always takes place between definite 



quantities 126 



84. The relative quantities of chemically re-acting matter. The 



action of magnesium and aluminium upon hydrogen sulphate 

 and hydrogen chloride 127 



85. The relative quantities of chemically re-acting matter. The 



re-action of silver nitrate with sodium chloride . . .129 



86. Some conditions of chemical change. Two kinds of complexity 



of matter 130 



Table of commoner elements 132 



87. Measurement of the mass of a litre of air .... 133 



88. Measurement of oxygen evolved when silver iodate is heated, 



and of the density of oxygen ...... 134 



89. Analysis of air by means of phosphorus 135 



90. Some effects of the atmosphere 136 



91. Changes observable when the temperature of copper oxide is 



raised in a current of hydrogen or coal-gas . . . .138 



