WeRead Powered by ReaderPub
Chemistry for beginners cover

Chemistry for beginners

Chapter 21: CHEMISTRY OF THE EARTH
By Hereward Carrington
Open in WeRead

Explore more books like this:

Science - Chemistry/Biochemistry

About This Book

A concise introduction traces chemistry's development from ancient Greek and alchemical ideas through medieval practice to modern atomic theory and the periodic law. It explains elements, atomic weights, valency, analysis and synthesis, and differentiates organic and inorganic chemistry, including catalysis, enzymes, and hormones. Practical topics include spectroscopic methods, industrial chemistry, instruments, and ocean salinity. Later chapters address radioactivity, intra-atomic energy, electrons, astrophysical applications, and discussions on the origin of life and the philosophical implications connecting chemical theory with metaphysical questions.

CHEMISTRY OF THE EARTH

The water constituting our seas, lakes, rivers and oceans; the air constituting our atmosphere; the materials of the earth on which we dwell—clay, rock, mud, granite, metals—all have been analyzed, and their chemical composition accurately determined. It has even been possible to measure the density and weight of our earth, and to calculate its age, from the salinity of its oceans. (Of this more anon.) But when it comes to ascertaining with great accuracy the chemical constitution of distant stars, that seems a feat well-nigh impossible, and unless the process by means of which it is accomplished were explained, it might very well be disbelieved.

How, then, can this be accomplished?

For our explanation, we must go back to a classical experiment made by Sir Isaac Newton. He proved that white light, when made to pass through a glass prism, is split up into a variety of colors. There are seven primary colors, constituting the visible spectrum. These are red, orange, yellow, green, blue, indigo and violet. We now know that there are both “ultra-violet” and “infra-red” rays, invisible to the eye, above and below the spectrum, but this was not known until long after. The essential fact is that light, when passed through a prism, is split up into its primary colors.