POTASSIUM CHLORIDE. 



a. Native. (Carnallite.) 



b. Pore, prepared from kelp. 



Note. The mineral carnallite is so called from its flesh colour. For 

 analysis of it, see Dana, Mineralogy, p. 118. 



51. CHBOMATE. K 2 Cr0 4 . (Yellow Chromate of Potash, Salt of 



Chrome, Neutral or Monochromate of Potassium.) 



a. Crystals. 



6. In coarse powder. 



Note. Specimen 6 contains traces of the sulphate and chlorate. For 

 fig. of crystal, see Gmelin, Chemistry, vol. i., pt. i., fig. 77; and vol. iv., 

 p. 144, for the description. 



52. BICHROMATE. K 2 Cr 4 Cr 3 . (Red Chromate of Potash, Acid 



Chromate of Potassium, Potassic Bichromate.) 

 a. Crystals, a commercial specimen, not quite pure. 

 6. Ditto, pure. 

 * c. A fine mass of crystals, presented by Mr. Greenhough. 



53. CITRATE. K 3 C 6 H 5 7 . (Tribasic or Neutral Citrate of Potash, 



Sal Absinthii Citratum.) 



a. Granular Powder (Potassa Citras, B.P.) 



b. Crystals. 



54. CYANIDE. KCy. 



a. Fused, impure. 



b. Ditto, purified. 



c. Crystals. 



55. FERRATE. K 2 Fe0 4 . 



a. Impure, amorphous. 



56. FERRICTANIDE. K 6 Fe 2 Cy 12 . (Red Prussiate of Potash, Ferri- 



cyanuret of Potassium.) 



a. Crystals. 



6. Ditto, coated with Prussian blue. 



Note. The coating of Prussian blue was probably caused by exposure 

 of the crystals to sunlight while they were still damp. For fig. of crystal 

 see Gmelin, Chemistry, vol. i., pt. i., fig. 66 ; and vol. vii., p. 470. 



57. FERROCTANIDE. K 4 Fe Cy 6 . 



a. Commercial specimen. 



6. Columnar mass of large crystals. 



Note. Specimen 6 was presented by Mr. Reid, in October, 1842. For 

 fig. of the crystal, see Per. Mat. Med., vol. i., p. 53^, fig. 85, and wooden 

 model in the central case in this Museum. 



58. HYDRARGYRO-CrANIDE. K 2 Hg Cy 4 . 



a. Crystals. 



59. HTDRARQTRO-IODIDE. 2(K I HgI 2 ) 3H 2 0. 



a. Crystals. (lodo-Hydrargyrate of Potassium.) 



