in the theory of value and prices.

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ratio 07/OR so that by getting it at less than he was willing to pay,he has gained the element 35 measured in corn. His gain is maxi-mum when he purchases such a quantity that its final utility equalsits price.

Fig. 39 applies to “ producer’s rent ” or “ gain,” substituting“ sale ” for “ purchase “ sell ” for “ buy.”

To express the gain in money the area M26 must be multiplied bythe price. On each cistern construct the curve 62 (fig. 38) and con-sider the area R.A26 to move front and back one unit (say one inch)so as to trace a volume (fig. 40) adjacent to the front cistern and

40.

again to movep inches further back so as to trace a volume adjacentto the back cistern.

The front volume giveB again the total utility measured in com-modity. The back volume gives the total utility measured in money.That is the whole back cistern and its adjacent volume represent themoney which if the individual paid he would neither gain nor lose,provided his marginal valuation of it is unchanged by the operation.The cistern portion is the money he actually pays and the outsidevolume 7, 10, 12, 9, 8, 11 is his “gain.” Likewise for the producer.

IU. GAIN A MAXIMUM.

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In the case of a single individual distributing a fixed income overvarious commodities under fixed prices the distribution actuallyTbans. Conn. Acad., Vol. IX. 7 July, 1892.

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