LIME. 107 



Carbonate of Soda. — (Sodje Carbonas, U. S.) 



Procured from the ashes of sea-weeds, in the impure forms of 

 kelp and barilla-; generally manufactured from the sulphate, by 

 decomposing it with carbonate of lime. It is in large, rhomboidal 

 crystals, efflorescent, very soluble in water ; taste alkaline ; unequal 

 in strength. Dose, 30 to 60 grs. ; — of the dried salt, 10 to 30 grs. 



Bicarbonate of Soda. — (Sod^e Bicarbonas, U. S.) 



Supercarbo?iate of Soda. — Prepared by passing carbonic acid gas 

 through a solution of the carbonate, and crystallizing at a low heat. 

 Usually occurs as a white powder, and contains some sesquicar- 

 bonate ; — not so soluble as the carbonate, but less disagreeable to 

 the taste. Given in dyspepsia, &c. ; also used in making soda and 

 seidlitz powders. Dose, 3ss. to 3j. 



Carbonates or Potassa. 



Already spoken of under Diuretics. As antacids, the carbonate 

 is given in the dose of 10 to 20 grains ; the bicarbonate^ in from 20 

 to 40 grains. The infusion of hickory ashes is sometimes used as 

 an antacid : it owes its efficacy to the carbonate of potassa which it 

 contains. 



Lime. — (Calx, U. S.) 



Used medicinally only in solution, under the name of lime-water 

 {aqua calcis) ; — made by dissolving lime in water, and keeping it in 

 well-stopped bottles, with a portion of lime undissolved, in order that 

 it may be always saturated. It is colourless, of an alkaline taste 

 and reaction ; combines with the carbonic acid of the air, and forms 

 a pellicle of the carbonate. Used generally in combination with 

 fresh milk, as a remedy for irritable stomach, — a tablespoonful of 

 each, taken every half hour. Externally, in combination with lin- 

 seed oil, as a liniment for burns. 



The carbonate is used internally in the form of Prepared chalk, 

 and prejKired oyster shells. Prepared chalk, [Greta preparata,) oc- 

 curs in the form of small, white, conical masses, insoluble in pure 

 water, somewhat soluble in carbonic acid water. It is astringent as 

 well as antacid, and is very useful in diarrhoeas accompanied by 

 acidity — particularly in children ; dose, 10 to 30 grains, every 

 hour or two. The Chalk tnixture (JSlisturce Cretce)^ is made by 

 rubbing up chalk with sugar and gum, and adding cinnamon-water. 

 Chalk is sometimes applied externally as an absorbent. 



Prepared oyster shells {Testa preparata), are made from the 

 common shells by grinding, &c., as for prepared chalk. They 

 differ from it only in containing a little animal matter. 



Uses, — The same. 



