“
Of the... similar new radio-elements... is still the only one [of] the compounds... prepared in a pure state, and for which the spectrum and atomic weight have been determined. As regards its... chemical character radium is... normal and its properties could have been predicted accurately for... its place in the . It is the last member of the... alkaline earths and stands in relation to as thorium does to in the periodic system. But... it possesses a radioactive character truly astounding. The energy it evolves... 133 calories per gram per hour. ...[T]he uniqueness of radium is due mainly to... its average life, 2440 years.., sufficiently long to... accumulate in... minerals.., yet short enough for the rate at which the energy... is liberated to be... surprising.
— FREDERICK SODDY