AbstractBöttcher's formula for the molecular refraction of dissolved electrolytes is used to interprete the refractive index versus concentration curve previously obtained for the aqueous solutions of some long‐chain anionic colloidal electrolytes.The plotting of the reciprocal of polarisabilicy of dissolved long‐chain anion as a function of\documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{{2{\rm n}^2 - 2}}{{2{\rm n}^2 + 2}} $$\end{document}under two different temperatures gives two straight lines A, B and non‐linear parts C, as being shown in Fig. 1.It is concluded that (1) the straight line A corresponds to a linear relation between\documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{1}{{\alpha *_{X^ -}}} $$\end{document}and\documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{{2n^2 - 2}}{{2n^2 + 1}} $$\end{document}for simply dissociated long‐chain anion X−, (2) the other straight line B to a same relation between\documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{\nu}{{\alpha *_{\left({^\alpha \nu} \right)^ -} \nu}} $$\end{document}and\documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{{2{\rm n}^2 - 2}}{{2{\rm n}^2 + 2}} $$\end{document}for ionic micelle (xν)−ν, after reaching the ultimately definite structure, and (3) the non‐linear parts C may be interpreted as a transition stage for long‐chain anions from the state of simply dissociated ones to the state of ionic micelle with its ultimate definite structure, and suggests that the formation of micelle with its ultimate definite structure may be accomplished gradually over a wider range of concentration, but not in