COUNTER-IRRITANTS. 321 



vein ; not by removing tlie inflammation from it, but by pro- 

 moting the formation of a large quantity of reparative lymph, 

 and hastening its further development into fibrous tissue, by 

 which the vessel is transformed at the inflamed part into a 

 fibrous cord. Now, if the curative action were due to the re- 

 moval of inflammation, we should find that in the first case the 

 relief would be only of a temporary nature ; the sinus w^ould still 

 remain, being generally the cause, and not the efiect, of the 

 morbid action ; and in the second, that the inflammation being 

 removed from the coats of the vein, the vessel would, upon re- 

 moval of the clot, become pervious. But such is not the case. 

 Let the clot be removed ever so often, it is sure to form again, 

 and nothing has the power of overcoming the inflammation of 

 the vessel until it has been transformed into an organized cord 

 — a process most materially hastened by the application of a 

 blister. 



I think it may therefore be accepted that external irritants — 

 whether they be simply rubefacients, producing a mere redness 

 of the skin, vesicants or blisters, which cause elevations of the 

 cuticle by fluid underneath it, or cauterization and setons, which 

 promote the suppurative action — remove lameness by assisting 

 nature in a process of repair. 



Mubefacients may be employed in the less severe forms of 

 lameness, in sprains of tendons, or in slight affection of joints, 

 along with rest and fomentations, after the more acute symp- 

 toms have passed away. 



Blisters. — It is usual to apply blisters in all cases of some 

 standing, when organic changes in the parts involved are sus- 

 pected. Before a blister is applied, the hair should be clipped 

 from the part, which, if dirty, ought to be washed, and when 

 dry, the blister to be applied with smart friction for about ten 

 minutes. To obtain the full effect of a blister, a quantity of 

 ointment is to be thickly laid on after the rubbing-in is com- 

 pleted. 



The best agent is cantharides, in the form of acetate, tincture, 

 or ointment ; to the limbs, the ointment in preference ; one part 

 of cantharides to twelve parts of lard or palm oil. If prepared 

 with a temperature equal to the boiling-point of water (212°), 

 it will be sufficiently strong, and will never blemish. It is 

 a mistake to think that the powdered flies should be mixed 



¥ 



