612 



Mr. W. A. Borodowsky on Absorption of 



A new series of curves (figs. 3 a and 4 a)> corresponding to 

 figs. 3 and 4, were then drawn, in which the depths of the 

 solution were taken as abscissse, and the corresponding 

 thicknesses of aluminium to give equal absorption were taken 



Fiar. 3 a. 



thickrvKS 0^ cm. 0Z- ■'%■■ '/6- 3.0 ■■ 



as ordinates. Supposing in the case of aluminium that the 

 abscissse correspond to the thickness of aluminium, the curve 

 for aluminium is obviously a straight line bisecting the angle 

 between the axes. 



For each concentration the curve obtained is a straight line 

 passiug very nearly through the origin. This shows that, for 

 a given concentration, the absorption in terms of aluminium 

 is directly proportional to the depth of the solution. A 

 slight divergence was observed for thin layers of the solutions. 

 This results from the bulging of the glass strips forming the 

 wedge in consequence of the forces of surface tension. 



