Why did the common memory fixate on salt, even if the payment was made in coin?

Answer

The perceived value of the essential commodity was more enduring than the transaction form.

The linguistic legacy fixed upon the salt itself because the essential nature of what the payment bought—its perceived value to the common person—was more enduring in public consciousness than the actual form of the transaction (coin).

Why did the common memory fixate on salt, even if the payment was made in coin?
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