238 ZINC OXIDE 



It relieves cutaneous tenderness and itching. In ery- 

 thema, in which it is often desirable to avoid moist dressings, 

 it is dusted over the tender surface mixed with four to six 

 parts of kaolin, ' Sanitas ' powder, or starch flour. In many 

 cases of erythema it is usefully conjoined with glycerin, 

 vaseline, or soft soap. Acute vesicular eczema is often 

 successfully treated by a thorough soaking with mercurous 

 oxide wash and the subsequent in-rubbing of zinc oxide 

 ointment or oleate. When there is much tenderness or 

 itching such dressings are mixed with or followed by applica- 

 tion of orthoform. After cleansing the meatus the oint- 

 ment is useful in canker of the ear of dogs, and in diseases 

 that simulate it. 



DOSES, etc. Horses and cattle take ^ij. to ^iv. ; dogs, 

 grs. ij. to grs. vj., given in bolus or solution. For external 

 use aqueous solutions are made with equal parts of zinc oxide 

 and borax or other alkaline salt or glycerin added to ensure 

 solution, with ten to thirty parts of water. It is also used 

 with subnitrate or oxide of bismuth. Liniments are prepared 

 with one part of oxide to five or six of olive oil, or other fatty 

 matter. Unguentum zinei is made with three parts of zinc 

 oxide, and seventeen parts of benzoated lard. Some 

 cutaneous complaints, in which ointments freely used are 

 apt to impair secretion and excretion, and others which 

 should not be wetted, are satisfactorily treated by pastes or 

 powders. Zinc oxide suits well for such purposes, and may 

 be applied mixed with kaolin, magnesium carbonate, 

 starch, iodoform, or boracic acid. 



Peroxide of zinc, or zinc perhydrol (Merck), is a white 

 powder, insoluble in water, and composed of equal parts of 

 zinc peroxide (Zn0 2 ), and zinc oxide (ZnO). It is said to 

 combine the disinfectant properties of oxygen with the 

 astringent effects of zinc oxide. Applied to open wounds it 

 is neither caustic nor irritant ; and in powder or ointment it 

 is valuable as a dressing for contusions, ulcers, dermatitis, 

 and eczema. For operation wounds it may be used in place 

 of iodoform. A pomade, made with five to twenty parts of 

 zinc peroxide and a hundred parts of vaseline, or lanoline, is a 

 convenient application for recent superficial wounds and 

 bruises. 



