The Ignis Fatuus is a vapor shining without heat.

I have been much amused at ye singular phenomena resulting from bringing of a needle into contact with a piece of amber or resin fricated on silke clothe. Ye flame putteth me in mind of sheet lightning on a small-how very small-scale.

Are not gross bodies and light convertible into one another; and may not bodies receive much of their activity from the particles of light which enter into their composition? The changing of bodies into light, and light into bodies, is very conformable to the course of Nature, which seems delighted with transmutations.

An object that is at rest will tend to stay at rest. An object that is in motion will tend to stay in motion.

You ask me how, with so much study, I manage to retene my health. Morpheus is my last companion; without 8 or 9 hours of him yr correspondent is not worth one scavenger's peruke. My practices did at ye first hurt my stomach, but now I eat heartily enou' as y' will see when I come down beside you.

Poetry is a kind of ingenious nonsense.

[1.] And first I suppose that there is diffused through all places an aethereal substance capable of contraction & dilatation, strongly elastick, & in a word, much like air in all respects, but far more subtile. 2. I suppose this aether pervades all gross bodies, but yet so as to stand rarer in their pores then in free spaces, & so much ye rarer as their pores are less ... 3. I suppose ye rarer aether within bodies & ye denser without them, not to be terminated in a mathematical superficies, but to grow gradually into one another.