Mill restores the balance by turning the process of circulation into direct barter and then smuggling into direct barter the character of buyer and seller borrowed by him from the process of circulation. To put it in his own confused language, during certain periods when all commodities are unsaleable there are really more buyers than sellers of one commodity, _money_, and more sellers than buyers of _all other money_, commodities; such was, e. g., the case at certain moments during the commercial crisis of 1857-58 in London and Hamburg. The metaphysical balance of purchases and sales amounts to this, that every purchase is a sale and every sale is a purchase, which is a poor consolation to the guardian of the commodity who can not bring about its sale and therefore can not buy.[71] The separation of sale and purchase makes possible a large number of fictitious transactions side by side with genuine trade before the final exchange between the producer and the consumer of commodities takes place. It enables a host of parasites to penetrate the process of production and exploit the separation. But this, again, means that with money as the universal form of labor under the capitalist system, there is _the possibility_ of the development of its contradictions. b. THE CIRCULATION OF MONEY. Actual circulation appears at first sight as a mass of purchases and sales accidentally taking place side by side. In buying as in selling, commodities and money always stand in the same mutual relation: the seller, on the side of the commodity; the buyer, on that of money. Money as a medium of circulation always appears therefore as _a means of purchase_; and in that way the difference in its destinations in the opposite phases of the metamorphosis of the commodity becomes indistinguishable.