Quote Originally Posted by Flickerdart View Post
Mercury is hydragyrum, so it doesn't seem a likely candidate for "abio".
It is actually mercury; popular thinking goes that it would have crossed into silver's territory had they used the full name, or sounded like some water elemental (hydrach?) had they shortened it, so instead they settled on "abio" to reflect the toxicity of mercury. Tin is the missing link in the order.