I saw in a dream a table where all the elements fell into place as required. Awakening, I immediately wrote it down on a piece of paper.

The elements, if arranged according to their atomic weights, exhibit an apparent periodicity of properties.

No law of nature, however general, has been established all at once; its recognition has always been preceded by many presentiments.

I have achieved an inner freedom.

There exists everywhere a medium in things, determined by equilibrium.

Work, look for peace and calm in work: You will find it nowhere else. Pleasures flit by -- they are only for yourself; work leaves a mark of long-lasting joy, work is for others.

The edifice of science not only requires material, but also a plan. Without the material, the plan alone is but a castle in the air-a mere possibility; whilst the material without a plan is but useless matter.