It is a universal condition of the enjoyable that the mind must believe in the existence of a law, and yet have a mystery to move about in.

The 2nd law of thermodynamics has the same degree of truth as the statement that if you throw a tumblerful of water into the sea, you cannot get the same tumblerful of water out again.

The student who uses home made apparatus, which is always going wrong, often learns more than one who has the use of carefully adjusted instruments, to which he is apt to trust and which he dares not take to pieces.

We can scarcely avoid the inference that light consists in the transverse undulations of the same medium which is the cause of electric and magnetic phenomena.

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.

That small word "Force," they make a barber's block, Ready to put on Meanings most strange and various, fit to shock Pupils of Newton.... The phrases of last century in this Linger to play tricks- Vis viva and Vis Mortua and Vis Acceleratrix:- Those long-nebbed words that to our text books still Cling by their titles, And from them creep, as entozoa will, Into our vitals. But see! Tait writes in lucid symbols clear One small equation; And Force becomes of Energy a mere Space-variation.

The true Logic for this world is the Calculus of Probabilities, which takes account of the magnitude of the probability.