The elements which are the most widely diffused have small atomic weights.

When the elements are arranged in vertical columns according to increasing atomic weight, so that the horizontal lines contain analogous elements again according to increasing atomic weight, an arrangement results from which several general conclusions may be drawn.

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

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.

If all the elements are arranged in the order of their atomic weights, a periodic repetition of properties is obtained. This is expressed by the law of periodicity.

Knowing how contented, free, and joyful is life in the world of science, one fervently wishes that many would enter its portals.

Elements which are similar as regards their chemical properties have atomic weights which are either of nearly the same value (eg. Pt, Ir, Os) or which increase regularly (eg. K, Ru, Cs).