219 
PHYSICAL AND MATHEMATICAL SECTION. 
Annual Meeting, March 26th, 1878. 
E. W. Binney, F.R.S., F.G.S., Vice-President of the Section^ 
in the Chair. 
The following gentlemen were elected officers of the 
Section for the ensuing year : — 
Ikmbntt. 
JOSEPH BAXENDELL, F.R.A.S. 
E. W. BINNEY, E.R.S., F.G.S. 
ALFRED BROTHERS, F.R.A.S. 
feasam. 
JAMES BOTTOMLEY, B.A., D.Sc. 
THOMAS MACKERETH, F.R.A.S., F.M.S. 
April 23rd, 1878. 
E. W. Binney, F.B.S., F.G.S., Vice-President of the Section, 
in the Chair. 
“ On some Colorimetrical Experiments,” by James Bot- 
tomley, B.A., D.Sc. 
If a white disc be sunk in a coloured solution, the in- 
tensity of the colour perceived will be a function of the 
depth of the disc and the quantity of colouring matter 
present. If, in any set of experiments, we make the 
intensity ot colour constant, then the depth of the disc will 
Proceedings— Lit. & Phil. Soc— Vol. XYIL— No. 14, Session 1877-8. 
