PREPARED CHALK 145 



gravity; with uric acid calculus, or those affected with 

 chronic rheumatism. The salts will not dissolve calculi in 

 the body, but prevent their formation. 



Water is extremely useful in such conditions. Lithium 

 citrate may be placed in the drinking water. Thirst should 

 be encouraged by the administration of salt on the food, and 

 high rectal injections may be given to create absorption of 

 water by this channel. Lithium salicylate is thought to be 

 the better salt for rheumatism. It is probable that treat- 

 ment with salicylic acid and lithium citrate would be more 

 satisfactory. 



SECTION IIL 



Alkaline Earth Metals : Calcium, Barium, Magnesium, 

 Aluminum and Cerium. 



Calcium. 



{The Metal Calcium is not Employed in Medicine.) 



Creta Pr^parata. Prepared Chalk. Ca C03. 

 (U. S. k B. P.) 



Synonym. — Drop chalk, E.; craie preparee, Fr.; prapa- 

 rirte kreide, G. 



Derivation. — Made from chalk by levigation, elutriation 

 and dessication. 



Properties. — A white, amorphous powder, often moulded 

 into conical drops ; odorless and tasteless ; permanent in 

 the air. Almost insoluble in water ; insoluble in alcohol. 



Incompatihles. — Sulphates and acids. 



Dose.—R., 5i.-ii. (30.-60.); C, 5 ii.-iv. (60.-120.); Sh. & 

 Sw., 3 ii.-iv. (8,-15.); D., gr.x.- 3 i. (.6-4.). 



PREPARATIONS. 



Pulvis Cretce Compositus, Compound Chalk Powder. (U. S. P.) 

 Chalk, 30; acacia, 20; sugar, 50. 

 Dose.— D., gr.x.- 3 i. (.6-4.). 



