SALTS OF BISMUTH 419 



has been recommended as a wash for mucous membranes or body 

 cavities. Solutions decompose when exposed to light but may be 

 kept for a long time if protected from it. It is used in from 2 to 5 

 per cent, solution in distilled boiled water intravenously, the dose 

 being for the horse 3 ss — ^j ; for the dog, gr. j — ij. For inunction 

 Crede's Ointment offers the best method of administration. This 

 is a 15 per cent, preparation of the drug with lard and wax. The 

 inunction is useful in local infections, and should be applied after the 

 skin has been scrubbed with soap and water and dried with alcohol. 

 Dieckerhoff has recommended collargol in the treatment of pur- 

 pura of the horse in daily intravenous doses of 25 mils of a 2 per 

 cent, solution. More recent results have not been so satisfactory and 

 at the present time the drug is rarely employed. 



BISMUTH 



Bismuth is official in the following forms: 



Bismuthi Subcarbonas. Bismuth subcarbonate, a white, in- 

 soluble powder, odorless and tasteless. 



Dose. H. and C, 3 j — iv; 4. — 15. Dog. gr. v — Ix; 0.3 — i. 



Bismuthi Subnitras. Bismuth Subnitrate. Character and 

 doses similar to the preceding drug. 



Preparation. Magma Bismuthi. Milk of bismuth. 



Dose. D. 3 ss — ij ; 2. — 8. 



Bismuthi Subsalicylas. Bismuth Subsalicylate. Characters 

 similar to the preceding salts. Dose one half that of the carbonate. 



Bismuthi Subgallas. Bismuth Subgallate, Dermatol. Yellow, 

 insoluble powder, dose same as the preceding. 



Bismuthi Citras. Bismiith citrate. Insoluble, white powder, 

 rarely used in medicine but is used in the manufacture of bismuth 

 and ammonium citrate. Dose same as for the subcarbonate. 



Bismuthi et Ammonii Citras. Bismuth and ammonium ci- 

 trate. White, soluble powder. Dose, same as for the carbonate. 



Action. Bismuth is used entirely for its local action. 



Externally and Locally. The various insoluble preparations 

 have a marked healing action when applied to mucous membranes 

 and raw surfaces. They dry the secretions and form a protective 

 covering to the wound. With the exception of the subnitrate their 

 action is purely mechanical and is due to fine particles of the powder 

 plugging the lymph and blood capillaries. The subnitrate is believed 

 to be more astringent and antiseptic than the others due to the 

 liberation of nitric acid in the presence of water and the secretions 

 of the tissues. 



The salts of bismuth act physically when given by mouth. They 

 adhere to the mucous membrane erf the stomach and protect it from 



