Mechanical engineering frequently uses continuum mechanics. It is rare in academic sciences. There are cases that continuum mechanics is needed to make some materials, e.g., for light emitting diode, in applied physics, especially, mass production. However, this mechanics is not sufficiently learned in applied physics. The theories in mechanical engineering are effective in such cases. We have to report results carefully to understand them in applied physics because the common knowledge in mechanical engineering is not common knowledge in sciences. This presentation deals with solid solution growth from liquid solution. There are fluid flows in the liquid solution. In the traditional calculations, the results are buried under errors. This presentation deals with a case without these flows to prepare to deal with these flows. The liquid solution is supersaturated just before growth. The temperature is constant during the growth. This presentation shows an analytic solution. This analytic solution derives that the composition of solid solution is constant. It becomes a baseline in numerical simulations.
