536 MATERIA MEDICA 



linen that h<id been soaked in vinegar, in which garlic, assafcc- 

 ida, pellitory of Spain, &c. had been steeped ; also by putting 

 balls between the grinders, composed of similar ingredients, or 

 others capable of stimulating the salivary glands, and bringing 

 on a discharge of saliva : these were called masticatories or 

 chewing l)all3, A late writer (Mr. Wilkinson) haa recommended 

 cliewing balls, composed of antimonial powder, gum, &c. in epi- 

 demic catarrh or distemper, when attended with sore throat and 

 difficulty of swallowing. 



SILVER. — Argentum. The only preparation this metal 

 affords is the lunar caustic, or nitrate of silver ; an application 

 of great importance in surgery, whether human or veterinary. 

 See Caustics, Lunar Caustic, and Argenti Nitras. 



SINAPISMS. — Catnplasma Sinajns, Stimulating poul- 

 tices, or liniments, in which mustard is a principal ingredient. 

 See Embrocations and Mustard. 



SNAKE-ROOT. — Pohjgala Senega. This, which is a peren- 

 nial plant, is a native of North America. It is inodorous, of a 

 sweetish taste on being first chewed, and afterwards hot and 

 pungent. It is a stimulant and diuretic, increasing the action of 

 the absorbents, and occasionally producing ptyalism. The idea 

 that this root counteracts the bites of serpents is now disregarded; 

 but it is considered a useful medicine in cases of weakness, 

 and may probably be employed with advantage in veterinary 

 practice. 



The dose is from two to four drachms or more, and is gene- 

 rally given with carbonate of ammonia, or salt of hartshorn, 

 camphor, and bark ; in some cases opium is added. See Tonics 

 and Antiseptics. 



SOAP. — ISapo. The various kinds of soap have all a strong 

 and diuretic quality ; and these ai'e Castile, Spanish, and pure 

 white soap. Soap is an useful ingredient in purgative as well as 

 diuretic preparations. 



The dose is from two or three drachms to an ounce, but It is 

 sometimes sflven in laro-er doses. 



Soft soap Is very useful in cleansing foul heels ; and when 

 mixed with oil of turpentine and spirit of wine, forms a good 

 embrocation for Indurated tumours, or callous swellings. See 

 Embrocations and Liniments. 



SODA ; Natron, or the mineral alkali. This Is procured 

 chiefly from the ashes of marine plants. Its medicinal proper- 

 ties are nearly the same as potash, but the prepared natron or 

 soda is sometimes preferred as an ingredient In purgative and 

 tonic medicines. 



The dose is from two to four drachms. 



There are various preparations of soda, as the carbonate of 

 soda (sodcB carbonas), which Is antacid and dcobstrucnt ; the dried 



