in the theory of value and prices.

93

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These curves are shown in figs, 29 and 30 (Jevons ), 31, 32 (Aus-pitz und Lieben), and 33, 34 (new). The first in each case is forconsumption the second for production.*

If Jevons ’ curve for consumption becomes a straight line, fig. 35,its equation is:f

x j+m = m -

Using the preceding table substituting for x 3 and y s we get inAuspitz und Lieben coordinates :

0

x—q

which integrated gives

2 qy a = 1mx a -x*+C

Since the curve must evidently pass through the origin, C = 0,and using new constants we may write

y a = ax a —fix,

which is a parabola (fig. 36).

* Jevons used no production curve. The one drawn is inserted to completethe comparison. Fleeming Jenkins’ Demand and Supply” curves are the sameas Jevons save that price replaces marginal utility.

f Gossen, Launhardt, WhewSll, and Tozer(the last two use no geometric analy-sis) employ such a linear supposition, though the meanings of their variables arenot identical. Launhardt’s equation.