It is usually repre- "N :C -.OH sented by the inset formula and is closely related to cyanic acid and cyamelide, the relationships existing between the three compounds being shown in the diagram (see also A.
Hantzsch, Ber., 1906, 39, p. 139): Ordinary temperature Cyamelide (CNOH) 3 Cyanic acid CNOH HO ions 1 High Cyanuric acid Decomposes with temperature
Both formula and experiment proved that an increase of pressure of one atmosphere elevated the transition point for about o 04° The same laws apply to cases of more complicated nature, and one of them, which deserves to be pursued further, is the mutual transformation of cyanuric acid, C 3 H 3 N 3 O 3, cyanic acid, Chno, and cyamelide (Chno).; the first corresponding to prismatic sulphur, stable at higher temperatures, the last to rhombic, the equilibrium-symbol being: cyamelide 1 .?
° cyanuric acid; the cyanic acid corresponds to sulphur vapour, being in equilibrium with either cyamelide or cyanuric acid at a maximum pressure, definite for each temperature.