Ptii-iv = 195.2.

The element platinum (Sp. platina, dim. of plata, plate, silver - the two metals resemble in appearance), like gold, occurs mostly in the free state and in combination with iridium, osmium, palladium, rhodium, ruthenium, etc., metals resembling it; also in ores containing gold, lead, iron, silver; comes mainly from Ural Mountains and California. It is silvery white, soft like copper, malleable, ductile, possesses high fusing-point and great resistance to chemicals, soluble in nitro-hydrochloric or nitrohydrobromic acid, good conductor of heat and electricity, sp. gr. 21.5; forms two series of compounds - platinous, PtCl2, and platinic, PtCl4.

Platini Chloridum. Platinic Chloride, PtCl4,5H2O. - (Syn., Fr. Perchlorure de Platine; Ger. Platinchlorid.)

Manufacture: Platinum 3 parts + hydrochloric acid 16 + nitric acid 7, evaporate nearly to dryness, redissolve in HC1, heat to expel HNO3, evaporate to dryness; contains 46 p. c. of platinum.

Preparation. - Platinic Chloride Test Solution: Chloroplatinic acid, H2PtCl6,6H2O, 2.6 Gm. dissolved in 20 Ml. (Cc.) distilled water.

Properties and Uses. - Seldom used in medicine, although the chloride has been employed with good results in constitutional syphilis in doses gr. 1/8-1/2 (.008-.03 Gm.); the injection (1 p. c.) has been effective in leucorrhoea, gleet, indolent ulcers.