"In your letter you apply the word imponderable to a molecule. Don't do that again. It may also be worth knowing that the aether cannot be molecular. If it were, it would be a gas, and a pint of it would have the same properties as regards heat, etc., as a pint of air, except that it would not be so heavy. Under what form (right or light) can an atom be imagined? Bezonian! speak or die! Now I must go to post with two dogs in the rain.—Your afft. friend"