The temperature–concentration diagram has been determined for the system: silver-nitrate–water, from 0 to 100% silver nitrate, with greater accuracy than has previously been attained (especially with regard to thermostatic control and method of analysis). The equilibrium curve exhibits a eutectic point at − 7.57 °C. and 46.9% silver nitrate and also a break at about 159° where solid silver nitrate passes from the rhombic to the rhombohedral form.