Mr. H. Hilton on van der Waals 1 Equation* 113 



•&*« 



The radius of curvature at any point is 



r64r 6 + %.E 3 -3a: + 2) 2 ] S. 

 1152a: 5 (.f-1) 



if this point is one where for the curve has a maximum or 



minimum value, this reduces to rr. 



V(.r — 1) 



Phil. Mag. S. G. Vol. 2. No. 7. Ji«ty 1901. I 



