It is not improbable that Heraclitus meant merely to imply that we perceive only our own sensations, and they of course are what they are;--that the image of the sun is an appearance, or sensation in our eyes, and, of course, an appearance can be neither more nor less than what it appears to be;--that the notion of the true size of the sun is not an image, or belonging either to the sense, or to the sensuous fancy, but is an imageless truth of the understanding obtained by intellectual deductions. He could not possibly mean what Sir T. B. supposes him to have meant; for if he had believed the sun to be no more than a mile distant from us, every tree and house must have shown its absurdity. ... In the following books I have endeavoured, wherever the author himself is in a vulgar error, as far as my knowledge extends, to give in the margin, either the demonstrated discoveries, or more probable opinions, of the present natural philosophy;--so that, independently of the entertainingness of the thoughts and tales, and the force and splendor of Sir Thomas Browne's diction and manner, you may at once learn from him the history of human fancies and superstitions, both when he detects them, and when he himself falls into them,--and from my notes, the real truth of things, or, at least, the highest degree of probability, at which human research has hitherto arrived. ... Book II. c. i. Production of crystal. Cold is the attractive or astringent power, comparatively uncounteracted by the dilative, the diminution of which is the proportional increase of the contractive. Hence the astringent, or power of negative magnetism, is the proper agent in cold, and the contractive, or oxygen, an allied and consequential power. 'Crystallum, non ex aqua, sed ex substantia metallorum communi confrigeratum dico'. As the equator, or mid point of the equatorial hemispherical line, is to the centre, so water is to gold. Hydrogen is to the electrical azote, as azote to the magnetic hydrogen. Ib. Crystal--will strike fire--and upon collision with steel send forth its sparks, not much inferiourly to a flint. It being, indeed, nothing else but pure flint. C. iii. And the magick thereof (the lodestone) is not safely to be believed, which was delivered by Orpheus, that sprinkled with water it will upon a question emit a voice not much unlike an infant.