I have discovered that a screw-shaped device such as this, if it is well made from starched linen, will rise in the air if turned quickly.

To such an extent does nature delight and abound in variety that among her trees there is not one plant to be found which is exactly like another; and not only among the plants, but among the boughs, the leaves and the fruits, you will not find one which is exactly similar to another.

I shall do down in history as the man who opened a door!

In life beauty perishes, but not in art.

A beautiful body perishes, but a work of art dies not.

There is no higher or lower knowledge, but one only, flowing out of experimentation.

Having wandered some distance among gloomy rocks, I came to the entrance of a great cavern ... Two contrary emotions arose in me: fear and desire--fear of the threatening dark cavern, desire to see whether there were any marvelous things in it.