in the theory of vahie and prices. 

 33. 34. 



93 



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 for 

 consumption the second for production.* 



If Jevons' curve for consumption becomes a straio-ht line, fio\ 35, 

 its equation is:f 



Using the preceding table substituting for x^ and y^ we get in 

 Auspitz und Lieben coordinates : 



35. 36. 37 



which integrated gives 



Since the curve must evidently pass through the origin, C 

 and using new constants we may write :]; 



which is a parabola (fig. 36). 



= 0, 



* Jevons used no production curve. The one drawn is inserted to complete 

 the comparison. Fleeming Jenkins' '' Demand and Supply " curves are the same 

 as Jevons save that price replaces marginal utility. 



^ f Gossen, Launhardt, Whewell, and Tozer (the last two use no geomctvir analy- 

 sis) employ such a linear supposition, though the meanings of their v;unab1.vs nve 

 not identical. | Launhardt's equation. 



