28 VETERINARY MATERIA MEDICA. 



of serum between the derma and epidermis, thus 

 constituting the blisters — cantharides, euphorbium, 

 mezereon. 



PuSTULANTS cause pustules and usually affect only 

 isolated parts of the skin — croton oil, tartar emetic, 

 silver nitrate. 



Caustics or Escharotics are agents which de- 

 stroy the tissues to which they are applied, by ab- 

 stracting the water from these tissues or by corrosive 

 oxidation — caustic potash, lime, zinc chloride, silver 

 nitrate, mineral acids. 



Astringents cause contraction of muscular fibre 

 and lessen secretion from mucous surfaces. 



Systemic Astringents act on the internal organs 

 through the circulation — viz., gallic acid. 



Local Astringents act upon the part to which 

 they are applied — tannin, alum, salts of copper, lead, 

 zinc, per-salts of iron. 



Styptics are local applications intended for check- 

 ing bleeding — as astringents of all kinds, cold, ice, etc. 



Hemostatics are agents given internally to stop 

 hemorrhage — dilute mineral acids, gallic acid, ergot, 

 digitalis, lead acetate, and oil of turpentine. 



Emollients and Demulcents are substances cal- 

 culated to soften, soothe, and protect tissues to which 

 they are applied. 



Emollients are applied to act externally — as oils, 

 fats, vaseline, starch, glycerin, flaxseed, or other 

 poultices. 



Demulcents are used for the same purpose inter- 

 nally. 



