236 ZINC AND ITS MEDICINAL COMPOUNDS 



are equally benefited by eight or ten grains each of lead 

 acetate and opium. In many of these cases, besides 

 being given by the mouth, it is also added to starch injec- 

 tions. 



Externally it is applied to check superficial, circumscribed 

 inflammation ; to soothe and heal burns, bruises, and irri- 

 table moist ulcers ; to cool and relieve strained, inflamed 

 tendons and joints ; in conjunction with a dose of physic, to 

 abate the itching of nettle-rash and erythema ; to remove 

 the irritation and heal the excoriations of herpes ; to limit 

 the surrounding inflammation of acne ; to arrest irritation 

 and discharge in eczema, in such cases being advantageously 

 alternated with dilute alkalies, sulphur or citrine ointment, 

 or yellow wash. It is applied in mucous or catarrhal 

 inflammation of the eye, but is unsuitable when there is 

 abrasion or rupture of the cornea, as insoluble lead albumi- 

 nates and sulphates are formed, causing opacity, which is 

 difficult to remove. 



DOSES, etc. Of the lead acetates, horses and cattle take 

 3ss. to 3i- ; calves and sheep, grs. x. to grs. xx. ; pigs, grs. ij. 

 to grs. vj. ; dogs. grs. j. to grs. iv., given in bolus or solution, 

 repeated once or twice daily. For external application, 

 sugar of lead is used in powder, ointment, or dissolved in 

 twenty to forty parts of water, with a little vinegar to in- 

 crease its solubility. Goulard's Extract, diluted with four 

 to six parts of linseed or olive oil, is a cooling application 

 for blistered or contused surfaces. An equally serviceable 

 astringent and anodyne is made with one part of extract 

 to six or eight of vaseline or glycerin. Equal parts of 

 extract and spirit, diluted with eight or ten parts of water, 

 make a useful refrigerant astringent. One part of lead 

 acetate and three-quarter part zinc sulphate, dissolved in 

 thirty or forty of water, constitute the familiar white lotion, 

 a serviceable astringent, analgesic, and antiseptic. 



ZINC AND ITS MEDICINAL COMPOUNDS 



Metallic zinc is obtained by roasting zinc blende, which 

 is a native sulphide, or calamine, which is a native car- 

 bonate. Zinc is a bluish- white metal, brittle at low and 



