86 MATER i A MEDIC A AND THERAPEUTICS. 



Preparations. 



i. Lotio Hydrargyri Nigra . Black Wash. 

 Calomel, 30 gr. ; Lime Water, 10 fl.oz. 



ii. Pilula Hydrargyri Subchloridi Com- 

 S/ posita. Plummer's Pill. Calomel, 1; Sulphur- 

 ated Antimony, 1 ; Guaiacum Resin, 2 ; Castor 

 Oil, 1. Dose, 5 to 10 gr. 



iii. Unguentum Hydrargyri Subchloridi. 

 ~ 



B. Hvdrargyri Perchlpridum. Perchloride of 



Mercury. " Corrosive sublimate." HgCl.,. 



Source. Made by subliming a mixture of Sul- 



phate of Mercury, Chloride of Sodium, and Black 



Oxide of Manganese. HgSO 4 -f 2NaCl = HgCl 2 + 



, Na 2 S0 4 . The manganese simply prevents the f or- 



Imation of calomel. 



Characters. Heavy colourless masses of pris- 

 matic crystals. Solubility, 1 in 20 of water. 



Incompatible with alkalies and their carbonates, 

 lime-water, tartar emetic, nitrate of silver, acetate 

 of lead, albumen, iodide of potassium, soaps, decoc- 

 tion of bark. 



Impurities. Fixed salts ; detected by not vola- 

 tilising. 



Dose.^ to i gr. 



Preparation*. 



i. Liquor Hydrargyri Ferchloridi. J gr. 

 in 1 fl.oz. ( r ^ gr. in 1 fl.dr.). Dose, 30 to 120 

 min. 



ii. Lotio Hydrargyri Flava. " Yellow 

 Wash." Corrosive Sublimate, 18 gr. ; Lime 

 Water, 10 fl.oz. 



From Hydrargyri PerchJoridwn are made : 



iii. Hydr-argyri lodidum Rubrum. Red 



Iodide of Mercury. HgI 2 . 



Source. Made by mixing hot solutions of 

 Perchloride of Mercury, and Iodide of Polas- 

 sium, and purifying the precipitate. HgCL + 

 2KI = Hgl, + 2KC1. 



Characters. A vermilion crystalline pow- 

 der. Soluble feebly in water, freely in ether. 



Jin purities. As in the perchloride. 



Dose. ^ to j gr. 



