If it’s Thursday, we’re down to number 33 in Fearless’ look
at the Caps and their positions in the periodic table…
Arsenic
Arsenic is one of those elements that conjures visions of a
skull and crossbones on a glass bottle, the poison of choice for mystery
writers. Before it took on cultural connotations, it recorded quite a history
on its own merits. Arsenic compounds
were known to Greeks in the fourth century.
As “orpiment” (arsenic trisulfide), it was important trade commodity in
the Roman Empire. In China it was used
for medicinal purposes. And, of course,
it was used as a poison, preferred for the difficulty in identifying it as the cause
of death (well, at least until the 1830’s when James Marsh published his
results on a method for detecting arsenic).
It does have other, less nefarious (not to mention less
lethal) uses. It was used as a wood
treatment, preserving it against insects, bacteria, and fungus, but less so in
the United States over the past decade or so.
It has had a variety of medicinal uses, used to combat parasite-caused
diseases and even cancer. In compound
form it has a wide range of uses – with lead in car batteries; with gallium in
semiconductors, lasers and light-emitting diodes. It has been used in pigments, fireworks, and
lead alloys for bullets. It has been
used in optical glass and in taxonomy to preserve samples. However, many of these applications have
fallen into disuse because of the toxic and environmental effects of arsenic in
larger concentrations.
Arsenic is one of those elements that has been known for quite some time, one that in small doses or in
compounds with other elements can have beneficial uses. At higher concentrations or larger doses it
can be quite harmful. Care must be taken
to find that balance between bane and benefit.
It is not unlike a hockey player who, while having been around for a while, might, in some situations, provide
quality minutes and a measure of intensity that is useful. However, that same player, if given to
overexposure (maybe getting top-four minutes when he is suited to something
less), might lead to problems for his team.
Arsenic… the “John Erskine” of the periodic table.
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