76 Botanic Drugs 



oil and may be used externally as an application 

 to painful joints, but should not be taken internally. 

 It would better be diluted, as it appears to be 

 stronger than the synthetic methyl salicylate. 

 OILS OF GAULTHERIA (wintergreen) and BETULA 

 (sweet birch) are about 90 per cent methyl sal- 

 icylate. Dose, 10 to 15 drops. SALICIN is given in 

 doses of 5 to 30 grains and is less energetic than 

 salicylic acid. It is well borne by the stomach 

 and is of slight toxicity. It is slow in action. XANOL 

 is a caffeine-sodio salicylate from natural oil and is 

 a cardiac stimulant. SALICYLIC ACID COMPOUNDS 

 are more or less insoluble, especially the esters, the 

 salicyl radical being liberated in the intestine or 

 after absorption. In practice these synthetic prepa- 

 rations are not superior in effect to sodium sal- 

 icylate, especially that from the natural oil. They 

 are, however, nearly tasteless, most of them, and are 

 very expensive. For a description of these synthetic 

 products see "New and Nonofficial Remedies"; 

 and for a description of the many salts of synthetic 

 salicylic acid see the general text-books. 



TANNIC ACID, TANNIN (U. S. P.). There are 

 many plants from which tannins may be derived. 

 Chemically they differ more or less, but they are 

 similar pharmacologically. The chief quality is 

 astringency dependent upon the power of precipi- 

 tating albumins. The value of the drug in hemor- 

 rhage is due to its precipitation of the blood pro- 

 teins, which coagulate, checking hemorrhage. From 

 this same power over albumen, tannic acid kills 

 some of the lower organisms, so that the coagulated 

 proteins produced by its local application reduces 



