Tim:
You're absolutely right, but in addition to the extreme toxicity of some of the mercury compounds, it's also the extreme ignorance of much of the public that causes the trouble. Or, maybe it's just moderate ignorance and no common sense, as in "a little knowledge can be a dangerous thing".
With ricin in the headlines recently, I guess we should be prepared for panic concerning castor oil spillage inthe nurse's office or maybe even something to do with the husks from wild rice. (Ricin does sound like rice, so they must be connected.) And, to be safe, we should probably take a closer look at any other compounds with carbon, hydrogen, oxygen and, I think, nitrogen in them. After all, it's for the children.
Wasn't sure about the nitrogen, so I just looked ricin up in in my Handbook of Chemistry and Physics and a 1971 edition of The Condensed Chemical Dictionary. No formula in either, but TCCD does detail exactly how it is extracted from castor beans - using just sodium chloride and magnesium sulfate. Hope our government has the good sense to ban that book, and at least keep an eye on people buying those chemicals if they can't ban them outright.
Think maybe I'm getting a little nuts. Better climb down from the soapbox now and take my pills.
John Martin