Graphite is "a soft black lustrous form of carbon that conducts electricity
and is used in lead pencils and electrolytic anodes, as a lubricant, and as a
moderator in nuclear reactors."  (From Merriam-Webster's Dictionary)  In
other words, it is pure carbon.  It is sold in its purest form as a lubricant
for mechanical things like locks and door hinges.  Pure carbon takes several
different forms: graphite, coal, and diamond.  The form it takes depends on
the pressure and temperature to which it has been subjected.

Charcoal is NOT what is formed when meat is charred.  There are other
chemicals, like nitrates, I believe, which form when meat is pan-fried or
cooked at very high temperatures.

Carbon by itself is not nutritious, but also not poisonous.  In fact,
activated charcoal is used in emergency rooms to absorb caustic poisons
ingested by someone.  Carbon is found in almost everything we eat, combined
with hydrogen and oxygen to make carbohydrates.  I don't think it's possible
to be allergic to carbon itself, but since it combines so easily with other
elements to create substances (like petroleum,  and carbon
tetrachloride--paint thinner), carbon-CONTAINING products can be a problem.

Hope this is enough of a chemistry lesson.

Carol (who hasn't even THOUGHT about chemistry since organic chemistry blew
her out of a pre-med major!)