xii Contents 



As is shown by experiments, p. 72. To what extent the 

 elastic force of air is diminished by the respiration of 

 animals, p. 73. The entrance of air into the blood is proved, 

 pp. 73-74. By what sort of channels the air has to be trans- 

 mitted into the blood, p. 74. Fire and life are sustained by 

 the same aerial particles, p. 75. Difficulties raised as to 

 what has been said, p. ^^. In how many ways the elastic 

 power of bodies may arise, p. 78. It is shown that the aerial 

 particles are composite, p. 79. And that they are hard, p. 

 So. Why water is more penetrating than air, p. 80. How 

 air loses elasticity by the deflagration of flame, p. 80. How 

 fire is kindled, p. 81. The igneous and vital particles of the 

 air are not the air itself but only the more subtle part of it, 

 p. 82. It is shown that not the air itself, but only the 

 igneous part of it is a constituent of nitre, p. 84. The 

 igneous particles are simil^arly present in air and in nitre, p. 

 54. Why an animal and a lamp shut up in a glass from 

 which air is excluded quickly expire, p. 84. Air unfit for 

 sustaining life and fire expands in a vacuum just like un- 

 injured air, p. 85. Why air always comes to the flame, p. 86. 

 Air given out from the lungs of animals has become lighter, 

 p. 86. Admiration of divine providence, p. 88. How nitro- 

 aerial particles can be restored to air which has been 

 deprived of them, p. 89. The element of fire is deposited in 

 the sun, p. 89. The celestial fires seem to burn without the 

 help of sulphureous particles, p. 89. On the element of cold, 

 p. 90. Why the sky appears blue, p. 91. How aerial 

 particles acquire elastic force, p. 91. On their figure, p. 92. 

 And their downward movement, p. 92. Why the north wind 

 comes from above, p. 93. The cause of the circulation of 

 the air, p. 93. 



CHAPTER VI 1 1.— Of Nitro-A£rial Spirit, in so far 



AS IT IS BREATHED BY ANIMALS. 



The nitro-aerial particles are transported into the mass of 

 the blood, p. 93. Air mixed with the fermenting particles of 

 substances loses elasticity, p. 94. The heating of contrary 

 salts when they effervesce together seems to depend upon 



