The preliminary investigations reported in the foregoing pages may be summarised thus:- It is to be hoped that this new and interesting approach introduces a new and more precise factor in explaining what soil colour is, to what extent it is due to absorption, to what extent it is due to scattering and reflection of light and in ascertaining soil genesis or formation under the influence of climate and geology. From the theories on the scattering of light, it may be possible to investigate the distribution of particle size and its effect, base exchange in relation to double layer of soil colloids or behaviour of soil colloids as acidoids, basoids and saloids.