Incidentally you would have to eat a vast amount of rhubarb to poison
yourself so don't lose sleep.

If you are talking about rhubarb leaves (as opposed to stalks), I
wouldn't suggest being the guinea pig on this one. I've seen
calculations based on the oxalic acid content, but it seems that there
is at least one unidentified toxin other than oxalic acid in the
leaves (at least according to
http://www.nlm.nih.gov/medlineplus/e...cle/002876.htm ).

Unfortunately, all the medical journal articles on rhubarb leaf
poisoning which I've run into are not online (not even abstracts) For
example, Death of a child from oxalic acid poisoning due to eating
rhubarb leaves.; Dtsch Med Wochenschr. (1964 Dec 11) 89:2379-81.