It was found that the refractive index of material of a certain prism varied as $1.5+\frac{0.004}{{\lambda }^2},$ where $\lambda$ is the wavelength of light used to measure the refractive index. The same material was then used to construct a thin prism of apex angle $10°$. Angles of minimum deviation $\left({\delta }_{\mathrm{m}}\right)$ of the prism were recorded for the sources with wavelengths ${\lambda }_1$ and ${\lambda }_2$ respectively. Then