173 



60. POTASSIUM IODIDE. K I. (Hydriodate of Potash.) 



a. Pure, in prismatic crystals. 



6. Ditto, in opaque cnbes. 



c. A mass of large crystals, presented by Messrs. G. 



Atkinson & Co. 



flote. Specimens a and c have a yellowish tinge, from the presence of 

 free iodine. A little carbonate of potassium, when present, prevents 

 discoloration, which always takes place when the pure iodide is exposed 

 to light. See P. J. [8] , vol. iv., p. 669. Specimen 6 owes its opacity to 

 excess of acid. See Note by Mr. Southall, P. J., I. c. 



61. lODATB. KI0 8 . 



a. Crystals, freed from iodide by alcohol. 



62. MANGANATE. K 2 Mn 4 . 



a. Fused. (Chameleon Mineral.) 



63. PERMANGANATE. K 2 Mn 9 8 . 



a. Crystals, a commercial specimen. 

 6. Ditto, pure, prepared by Mr. Siebold. 

 Note. For the method by which specimen 6 was prepared, see P. J., 

 [8] , vol. vi., p. 441. 



64. NITRATE. K N O s . (Nitre, Saltpetre, Prismatic Nitre.) 



a. Crude. 



6. A commercial specimen. 

 c. Pure. 

 * d. Very large crystals. 



e. Fused, in flat circular cakes. (Sal Prunella, Crystal 



Mineral, Nitrum Tdbulatum.) 



f. Ditto, in small globes. (Sal Prunella Balls.) 



Note. Specimen c is the kind used in the preparation of gunpowder, 

 for the manufacture of which it must be very pure. For fig. of the 

 crystals, see Per. Mat. Med., vol. L, p. 540. 



65. NITRITE. KNO a . 



a. Fused, impure. 



b. Purified by solution in alcohol. 



Note. Specimen a probably contains some nitrate. 



66. OSMIATE. K 2 Os 4 , 2H 8 0. 



t a. In powder. 



67. OXALATE. K 2 C 2 O^HaO. 



a. Crystals. 



68. BINOXALATE. 'K H C 2 4 , 2 H 2 0. (Dioxalate of Potassium, Dipo- 



tassic Oxalate, Salt of Sorrel.) 



a. Crystals. 



Note. This is the salt found in wood sorrel (Oxalis Aeetotella, I,.), 

 five hundred parts of the plant yielding about four parts of the salt. Bee 

 Per. Mat. Med., vol. H., pi, ii., p. 414. 



