Is it not thus, that fire is amassed and makes the greatest part of the substance of combustible bodies?
Perhaps, when this globe was first formed, and its original particles took their place at certain distances from the centre, in proportion to their greater or less gravity, the fluid fire, attracted towards that centre, might in great part be obliged, as lightest, to take place above the rest, and thus form the sphere of fire above supposed, which would afterwards be continually diminishing by the substance it afforded to organised bodies, and the quantity restored to it again, by the burning or other separating of the parts of those bodies.
Is not the natural heat of animals thus produced, by separating in digestion the parts of food, and setting their fire at liberty?
Is it not this sphere of fire which kindles the wandering globes that sometimes pass through it in our course round the sun, have their surface kindled by it, and burst when their included air is greatly rarefied by the heat on their burning surfaces?
May it not have been from such considerations that the ancient philosophers supposed a sphere of fire to exist above the air of our atmosphere?
B. FRANKLIN.
TO MR. BODOIN.
[Queries and Conjectures relating to Magnetism and the Theory of the Earth.]
[No date.]