The Romance of Modern Chemistry

CHEMISTRY OF THE STARS How different is the outlook nowadays! Much in- formation is available as to the actual elements of which the sun and stars are composed, and it may with truth be said that we know more about the chemical composi- tion of the heavens above than about that of the earth beneath. For man, with all his wonderful achievements, has scratched only the surface of the globe, and we can but speculate about the materials of which the interior is composed. It is, indeed, exceedingly probable that large quantities of iron exist in the interior of the earth, firstly, on account of the fact of terrestrial magnetism, and secondly, because the average density of the earth as a whole is considerably greater than the average density of the crust—pointing to the presence of some heavy metallic material at lower depths. But no direct evidence is forthcoming as to the actual composition of the interior of our globe. If a scientist were asked, however, to name some of the materials of which the sun is composed, he would be ready with an unhesitating answer, and this would be the case also in regard to many of the stars. How has this come about ? How is it that we can speak now so confidently about the constitution of heavenly bodies, whose distance is measured in millions of miles, and whose very presence in the sky speaks so eloquently of the unattainable and the mysterious ? We certainly cannot travel to the heavenly bodies in order to study their chemical composition, but we do have occasional visitors to our planet from celestial spaces. These are the meteorites, the falling of which from the sky has excited both fear and wonder in the breast of man, and the life-history of which scientists so much desire to know. Some consider that meteorites are 204 nan