Sentence:  The only use of it [money] which is interdicted is to put it in circulation again after having diminished its weight by <WSD>sweating</WSD>, or otherwise, because the quantity of metal contains is no longer consistent with its impression. 
Meaning of the word marked with <WSD> tags:  To remove a portion of (a coin), as by shaking it with others in a bag, so that the friction wears off a small quantity of the metal.