short, the quantity theory asserts that (provided velocity of circulation and volume of trade are unchanged) if we increase the _number_ of dollars, whether by renaming coins, or by debasing coins, or by increasing coinage, or by any other means, prices will be increased in the same proportion. It is the number, and not the weight, that is essential. This fact needs great emphasis. It is a fact which differentiates money from all other goods and explains the peculiar manner in which its purchasing power is related to other goods. Sugar, for instance, has a specific desirability dependent on its quantity in pounds. Money has no such quality. The value of sugar depends on its _actual quantity_. If the quantity of sugar is changed from 1,000,000 pounds to 1,000,000 hundredweight, it does not follow that a hundredweight will have the value previously possessed by a pound. But if money in circulation is changed from 1,000,000 units of one weight to 1,000,000 units of another weight, the value of each unit will remain unchanged." (Irving Fisher, _Purchasing Power of Money_, pp. 31-32.) To the same effect is Nicholson's exposition, in which the money is assumed to consist of dodo-bones, the most useless substance that Nicholson could think of. For the quantity theory, prices are determined by the _numbers_ of goods and dollars that are to be exchanged for one another, and not by the _values_ of the goods and dollars;--indeed, for the quantity theory, "value" commonly has no meaning apart from the prices which are supposed to be adequately explained by the mechanical relations of numbers.