Two of the casters contained salt and pepper, but what went into the third...

Two of the casters contained salt and pepper, but what went into the third caster is unknown. It is generally presumed to have been dried mustard, but that is really because no one can think of anything more likely. "No satisfactory alternative has ever been suggested" is how the food historian Gerard Brett has put it. In fact, there is no evidence to suggest that mustard was ever desired or utilized in such ready fashion by diners at any time in history. Probably for this reason, by Mr. Marsham's day the third caster was rapidly disappearing

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