"King of Poisons"  "King of Poisons" by John Parascandola.
(Algerina Perna, Baltimore Sun / February 26, 2013)  For such a
long time, arsenic was the perfect poison.  It is odorless,
colorless and tasteless, so it's difficult to detect when
slipped into a food or beverage. Its effects are gradual and
cumulative — deflecting suspicion from the killer. The symptoms
of arsenic poisoning mimic those of other diseases common in the
19th century, such as cholera and dysentery.  Because the
elemental form of arsenic occurs naturally in the environment,
it is inexpensive and easily obtained. And until a clever
British chemist named James Marsh devised a test in the 1830s,
it was impossible to trace the poison in the human body.  No
wonder Rockville resident John Parascandola dubs arsenic "The
King of Poisons" in his readable, newly published history.
Parascandola, 71, retired as the historian for the U.S. Public
Health Service and currently teaches the history of modern
biology and of poisons at the University of Ma