Abstract: | I. The fact, that the blue violet colour of the microcosimic salt bead of cobalt is changed into blue by addition of Na2CO3 K2CO3, K2CO3 NA2HPO4 or NA3PO4is explained by the formation of pyrophosphate in the melt. II. K2Na2P2O7 if melted together with CoCl2 forms blue porcelaneous masses, completely soluble in water. |