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).
We could live at the present day without a Plato, but a double number of Newtons is required to discover the secrets of nature, and to bring life into harmony with the laws of nature.
No law of nature, however general, has been established all at once; its recognition has always been preceded by many presentiments.
I want you to have this feeling too - it is my moral responsibility to help you achieve this inner freedom.
Pleasures flit by - they are only for yourself; work leaves a mark of long-lasting joy, work is for others.
The most all penetrating spirit before which will open the possibility of tilting not tables, but planets, is the spirit of free human inquiry. Believe only in that.
