The Romance of Modern Chemistry

SMALL CAUSES; GREAT EFFECTS view is adopted that this platinum solution is really a suspension of exceedingly minute particles, so tiny that they can find their way through the pores of filtering- paper. However that may be, there is no doubt that platinum in this condition is intensely active from the catalytic point of view, as shown, for instance, by its effect in upsetting the equilibrium of hydrogen peroxide. This is a substance which, in water solution, is applied as a bleaching agent for hair, ivory, and old pictures. Chemi- cally, it is a very interesting substance, being closely related to water; its molecule, in fact, is a molecule of water, to which an extra atom of oxygen has been tacked on. The attachment, however, is not very secure, and the result is that hydrogen peroxide is readily de- composed into water and oxygen. This chemical action, this decomposition, is accelerated in quite a remarkable manner by the addition of a little platinum solution to the hydrogen peroxide. Thus if we were to take dilute hydrogen peroxide and add to it so much platinum solution that a pint of the mixture contained i scrwth of an ounce of platinum, the decomposition of the hydrogen peroxide would be complete in about two hours; if no platinum solution were added the hydrogen peroxide would lose practically none of its oxygen in that time. Perhaps a still more convincing proof of the catalytic power of this platinum solution is obtained by shaking some of it in a flask with a mixture of hydrogen and oxygen. In ordinary circumstances these two gases require to be strongly heated before they will combine to form water, but under the persuasive influence of the platinum solution they unite at the temperature of the room, slowly but steadily and without any fuss. The 333