By definition, a chemist only believes in the existence of a new substance when he has seen the substance, touched it, weighed and examined it, confronted it with acids, bottled it, and when he has determined its "atomic weight."


Madame Curie - Chapter XIII (p. 165), The Literary Guild of America, Inc. 1937


By definition, a chemist only believes in the existence of a new substance when he has seen the substance, touched it, weighed and examined it,...

By definition, a chemist only believes in the existence of a new substance when he has seen the substance, touched it, weighed and examined it,...

By definition, a chemist only believes in the existence of a new substance when he has seen the substance, touched it, weighed and examined it,...

By definition, a chemist only believes in the existence of a new substance when he has seen the substance, touched it, weighed and examined it,...