How valuable is salt? 40 million tons are required each year to fill our needs. Homer called it divine. Plato called it a "substance dear to the gods." Shakespeare mentioned salt 17 times in his plays. Perhaps Leonard da Vinci wanted to send a subtle message about purity lost when he painted "The last Supper." In that painting an overturned salt cellar is conspicuously placed before Judas. In ancient Greece a far-flung trade involving the exchange of salt for slaves gave rise to the expression, "...not worth his salt." Special salt rations were given to Roman soldiers and known as "Solarium Argentums" the forerunner of the English word "salary." Thousands of Napoleon?s troops died during his retreat from Moscow because their wounds would not heal--their bodies lacked
...