HYDRARGYR UM. 8 7 



Preparation. 



TJnguentum Hydrargyri lodidi Rubri. 



] in 28. 



iv. Hydrargyrum Ammoniatmn. Am- 

 moniated Mercury. " White Precipitate." 

 NH 2 HgCl. 



Source. Made by precipitating a solution 

 of Perchloride of Mercury with Solution of 

 Ammonia. HgCL, + 2NH 4 HO = NH 2 HgCl + 



NH 4 C1 + 2H,0. 



'Characters. An opaque white powder, in- 

 soluble in water, spirit, and ether. 



Impurities. As in the perchloride. 



Preparation. 



IJnguentum Hydrargyri Ammoniati. 

 1 in ?L 



v. Hydrargyri Oxidum FlavTim. Yellow 

 Oxide of Mercury. HgO. 



Source. Made by precipitating a solution 

 of Perchloride of Mercury with a Solution of 

 Soda. 



Characters. A yellow powder. 



Impurities. As in the perchloride. 



i. Liquor Hydrargyri Nitratis Acidus. Nitrate 

 of Mercury, Hg2NO 3 , in solution in nitric acid. 



Source. Made by dissolving Mercury in Nitric Acid 

 and Water. 



Characters. A colourless, strongly-acid liquid. 



Impurity. Subnitrate of mercury; detected by 

 giving precipitate when dropped into diluted hydrochloric 

 acid. 



j. Unguentum Hydrargyri Nitratis. Citrinn 

 Ointment. Made by adding Lard melted in Olive Oil 

 to a solution of Mercury in Nitric Acid. 



Non-officinal Preparations o 



Qlcate of Merciiyy. Made by dissolving "> to 20 per 

 cent, of Yellow Oxide of Mercury inOlrie A<-M. 



Donovan's Solution. Solution of Hydriodate of 

 Mercury and Arsenic. Dose, 10 to 30 min. 



