ARSENICUM. 95 



5. Liquor Hydrargyri Nitratis Acidus, and the Ointment 

 of the Nitrate. These are not usnl in syphilis; but the former 

 is used as a caustic in lupus and other limited growths and 

 ulcers of the skin ; while the ointment is of value as a stimulant 

 in cases of chronic skin disease, and is applied to the edges of 

 the eyelids in chronic inflammation and ulceration of the hair 

 follicles. 



Precautions in the use of mercurials. Mercury must not j 

 be given as an alterative, antiphlogistic, or antisyphilitic 

 remedy in persons with anaemia or debility, unless these are 

 distinctly referable to syphilis, and even then it must be em- 

 ployed with caution. Tuberculosis and kidney disease also} 

 centra-indicate the use of mercury ; and certain individuals will 

 occasionally be met with in whom even small doses of calomel 

 or blue pill quickly induce hydrargyrism by a kind of idio- 

 syncrasy. In every instance the patient must be carefully 

 nourished, as we have said. On the contrary, children even 

 infants bear mercury very well, although the prolonged ad- 

 ministration of the metal to them appears to produce a peculiar 

 change in the permanent teeth when they appear, which is 

 extremely unsightly ("mercurial teeth " of Hutchinson). 



GROUP III. 



THE METALLOIDS. 



/AKSENICUM. ARSENIC. As. 73. 



Acidiiiii ArseilJQSUlll, Arsenious Acid. \Vhito 

 Arsenic. As^g. 



'<?. An anhydrous acid, obtained by roasting Arsenical 

 Ores, and purified by sublimation. 



Characters. A heavy white powder, or stratified opaque 

 Solubility, 1 in 100 of cold water ; 1 in 20 of boiling 

 water. Incompatibles : Salts of iron; magnesia, lim> - 

 aiid astringent m;r 



LnjtK) itifs. Limr salts ; detected by non-volatility. 



Lose. fa to ^ gr. in solution. 



Preparations. 



a. Liquor Arsenicalis. " Fowler's Solution.'* 

 Source. Made by dissolving Arsenious Acid and 

 Carbonate of Potash in Wat.T, and culuurin.u 1 with Com- 

 pound Tincture of La vender. 4 gr. in 1 ll.oz. 



