If it’s Thursday, we’re down to number 33 in Fearless’ look at the Caps and their positions in the periodic table…
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.