io6 MATERIA MEDIC A AND THERAPEUTICS. 



until the skin becomes moist and cool, when it may be 

 stopped. 



The unquestionable value of Plummer's Pill would appear 

 to be partly referable in the same way to the action of anti- 

 mony not only on nutrition, but on the various organs of 

 elimination, including the skin and the kidneys. 



BISMUTHUM. BISMUTH. Bi. 210. 



A crystalline metal; as met with in commerce it 

 is generally impure. 



From Bismuthum is made : 



Bismuthum PurincatunL Purified Bismuth. 



Source. Made by heating Bismuth with Nitrate of 

 Potash. 



Characters. A crystalline metal of a greyish-white 

 colour, with a roseate tinge. 



Impurity. Copper ; giving coloured reactions. 



From Bismuthum Purificatum are made : 



a. Bismuth! Subnitras. Subnitrate of Bis- 

 muth. White Bismuth. BiON0 3 H 2 O. 



Source. Made (1) by dissolving Purified Bis- 

 muth in Nitric Acid ; and (2) pouring the product into 

 Water. (1) Bi 2 + 8HN0 3 = 2(Bi3N0 3 ) + 2NO 4- 

 4H 2 0. (2) Bi3N0 3 + H 2 == BiON0 3 + 2HNO 3 . 



Characters. A heavy white powder, in minute 

 crystalline scales ; insoluble in water. 



Impurities. Carbonate of lead; giving pre- 

 cipitate with H 2 S0 4 when dissolved in HN0 3 ; 

 arsenic ; and chlorides. 



Dose.b to 20 gr. 



Preparation. 

 i. Trochisci Bismuthi. 2 gr. Subnitrate 



of Bismuth in each, Carbonate of Lime, and 



the usual ingredients of a lozenge. Dose, I to 6. 



from Bismuthi Subnitras is made : 



ii. Bismuthi Oxidum. Oxide of Bismuth. 



Bi 2 3 . 



Source. Made by boiling Subnitrate of 



Bismuth in Solution of Soda. 



Characters. A dull lemon-yellow powder ; 



insoluble in water, soluble in nitric acid mixed 



with half its volume of water. 



