490 VEGETABLE DKUGS 



malarial attack, will usually prevent it. A single large dose 

 should be given once daily for several days thereafter. When 

 the disease is severe, treatment may also be pursued by the 

 rectal and hypodermic methods at the same time that 

 quinine is given by the mouth. A purge of aloes and calomel 

 should be exhibited prior to the administration of quinine in 

 the treatment of malaria. 



Class 2.— Salicylic Acid, Salicin, Salol, Oil of 

 Gaultheria and Methyl Salicylate. 



, AciDUM Salicylicum. Salicylic Acid. HCjHjO,. 



(U. S. & B. P.) 



Synonym. — Acid salicylique, Fr. ; salicylsaiire, G. 



An organic acid, existing naturally in combination in 

 various plants, but chiefly prepared synthetically from car- 

 bolic acid. 



Derivation. — Made by passing carbonic dioxide through 

 sodium carbolate at a temperature of 428° F. (220°C). 

 2 Na CeHjO (sodium carbolate) + CO^ = Na^CiH^Oj (sodium 

 salicylate) + CsHjO (phenol). Sodium salicylate is treated 

 with hydrochloric acid, when salicylic acid is precipitated. 

 Na,C,HA -h 2 H CI = HC,H,03 + 2 Na CI. 



Properties. — Light, fine, white, prismatic needles, or a 

 light, white, crystalline powder ; odorless, having a sweetish, 

 afterward acrid taste, and permanent in the air. Soluble in 

 about 450 parts of cold water, and in 2.4 parts of alcohol ; 

 in 14 parts of boiling water, and very soluble in boiling 

 alcohol. Also soluble in 2 parts of ether, 2 parts of absolute 

 alcohol, and 80 parts of chloroform. 



Incompatible. — Spirit of nitrous ether. 



Impurities. — In artificial salicylic acid, metacreosotic and 

 orthocreosotic acids. 



Dose.—B.. & a, 3ii--5i. (8.-30.); Sh., 3i.-iv. (4.-15.); 

 Sw., 3 ss.-i. (2.4.) ; D., gr.v.-xxx. (.3-2.). 



Preparation. — Ungtmntum Acidi Salicylici (3 per cent.), B. P. 



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