ARNICA 523 



cells, surrounding the short, yellowish wood wedges, and 

 large, spongy pith. The roots numerous, thin, fragile; 

 grayish-brown, with a thick bark containing a circle of resin 

 cells. Odor somewhat aromatic ; taste pungently aromatic 

 and bitter. 



Gonstittcents. — Identical with those of flowers. 



Z)ose.— Same as flowers. 



PREPARATION. 



Tincfwa Amicce. (B. P.) 

 Dose.—S., |i.-ii. t30.-60);D., 3 ss.-i. (3.-4.). 



Action and Uses. — Externally, arnica, especially the tinc- 

 ture of the flowers, increases the vascularity of the integu- 

 ment, and may cause various grades of superficial inflamma- 

 tion on sensitive skins if not properly diluted. Internally, 

 the drug stimulates the mucous membrane of the digestive 

 tract, and is stomachic and carminative. Arnica is eliminated 

 by the kidneys and mucous membranes and stimulates these 

 parts during its excretion. Arnica slows and stimulates the 

 heart and increases vascular tension in medicinal doses, 

 while large doses augment the frequency of the pulse. This 

 action follows, first, stimulation, and later, depression of the 

 inhibitory apparatus. Toxic quantities occasion gastro- 

 intestinal irritation and nervous symptoms, as ^^iddiness, 

 stupor, delirium, insensibility, and convulsions ; with rapid, 

 feeble pulse and sometimes syncope. 



The only rational use for arnica is in stimulating the 

 skin in sprains and bruises. The tincture of the flowers is 

 generally diluted with water (1-12) for this purpose. It is 

 doubtful if it is more serviceable than alcohol in these con- 

 ditions.. There is no sufficient evidence to show that arnica 

 possesses any therapeutic value when given internally, 

 although it has been used and is recommended for dysentery, 

 chronic bronchitis, rheumatism, nervous disorders, etc. 



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