Primo Levi
There are the so-called inert gases in the air we breathe. They bear curious Greek names of erudite derivation which mean "the New," "the Hidden," "the Inactive," and "the Alien." They are indeed so inert, so satisfied with their condition, that they do not interfere in any chemical reaction, do not combine with any other element, and for precisely this reason have gone undetected for centuries.
