An Overview for the General Reader The fact that silicone rubber boots made those footprints on the moon, and that other silicone polymers made possible the construc­ tion and functioning of space suits and space vehicles, has led to the general belief that silicones are very modem materials conjured up to meet the needs of space travel. Actually, though, silicone chemis­ try has deep roots in human history, dating from the dawn of the race and extending through all of geology, mineralogy, and the ancient ceramic arts. This little book seeks to put the development of silicone materials in perspective as part of the fascinating involvement of the element silicon in our daily lives, from the stuff the earth and the moon are made of to the modem use of ultra­ pure silicon in transistors and computers, and the use of ordi­ nary elementary silicon to make silicone rubber, silicone oil, sili­ cone resins, and silicon or silicone-containing polishes, drugs, and fragrances. Of course these are not our only connections with silicon. The natural compounds of silicon and oxygen (the silicates) are the starting materials for making bricks, tile, cement, glass, and a host of modem ceramic products. The widespread usefulness of silicon and its compounds comes about for two reasons: first, there is so much of it, and second, it is so versatile.