Oxigênio e cálcio em Steiner (2007)
In such ways as these we can look into the life and growth of all that goes on in and above the surface of the soil. Now you must also include this fact: the limestone-nature has in it a wonderful kinship to the world of human cravings. See how it all becomes organic and alive! Take the chalk or limestone when it is still in the form of its element — as calcium. Then indeed it gives no rest at all. It wants to feel and fill itself at all costs; it wants to become quicklime that is, to unite its calcium with oxygen. Even then it is not satisfied, but craves for all sorts of things — wants to absorb all manner of metallic acids, or even bitumen which is scarcely mineral at all. It wants to draw everything to itself. Down there in the ground it unfolds a regular craving-nature. (Steiner 2007:27)
STEINER, Rudolf. 2007. The Agriculture Course. (Trans.: George Adams) Shrewsbury: Wilding & Son Ltd.