all of us, buttake in just a little too muc  to e certain elements is a relic of tion. Stleno actually  mineral requirements. Modern cattleneed quite a lot of copper because ts of Europe and Africa olerance for elements is directly proportionate to trogen and tom is divided among all ts.

    abundance in t. e o expect, and in some cases actually need,tiny amounts of rare elements t accumulate in t . But step uptiny amount, and ly understood. No one kno ofarsenic is necessary for our . Some auties say it is; some not. All t iscertain is t too muc will kill you.

    ties of ts can become more curious still whey are combined.

    Oxygen and ance, are t combustion-friendly elements around,but put togetible er.

    3Odder still in combination aresodium, one of t unstable of all elements, and c toxic. Drop asmall lump of pure sodium into ordinary er and it o kill.

    Coriously rations forkilling microorganisms (it’s c is lethal.

    C of c orld ar. And,as many a sore-eyed stest, even in exceedingly dilute form t appreciate it. Yet put ty elements toget do you get? Sodiumcable salt.

    By and large, if an element doesn’t naturally find its o our systems—if it isn’tsoluble in er, say—end to be intolerant of it. Lead poisons us because o it until o fas into food vessels and pipes for plumbing. (Notincidentally, lead’s symbol is Pb, for tin plumbum, t of t to be. As o mention mercury, cadmium, and all trial pollutants inely dose ourselves) does not leave us a gre