678 LOTHIAS: BEER’S LhW ASD ITS USE IN .WALYSIS [Analyst, 1’01. $8 Beer’s Law and its Use in Analysis A Review BY G. I;. LOTHIAX ( L‘w ivevsily o j Exefer, Deparlrnenf of Physics, The Washington Singev Lnbovafories, Prigice o j Walcs Road, Exetsr) SUMMARY OF COSTESTS Introduction : dcduction of Beer’s la