A Treasury of World Science

acid actinium action angle animals appear atomic weight barium bismuth body carbolic acid cathode rays cause cells characters chemical chloride circle circuit color common air conductor constant containing cylinder deflexion described direction distance earth effect electric current electromotive force elements equal existence experiments fact fluid force galvanometer glass greater heat hybrids hypothesis inflammable inflammable air length less light magnetic Marie Curie mass mathematics matter means measure metal method motion move nature observed obtained occur orbits oscillation oxide particles pass phenomena phosphoric acid pitchblende plane plants plates pole pollen polonium position present principle processes produced properties proportion proposition protoactinium quantity radiation radioactive radium radium chloride ratio respiration result salt seeds side solution space sparks species stars straight line substance supposed surface temperature theory things thorium tion tube uranium velocity voltaic pile waves wire