MEDICINES AND THEIR CLASSES. 35 



Infusions are made by digesting vegetable substances 

 or drugs in hot water (usually 1 part of drugs to 20 of 

 water) 15 minutes to 2 hours. Avoid boiling. 



Lotions (washes) are watery solutions for external use, 

 especially in chronic skin diseases. Strong lotions may be 

 used as counter-irritants. Lotions for the eye are usually 

 called collyria. 



Narcotics are soothers as well as stupefiers. Opium, 

 morphine, ether, chloroform, aconite, belladonna, digitalis, 

 hyoscyamus, stramonium, conium, &c. 



Plasters usually contain lead oxide, conjoined with 

 resin, wax, soap, fats, tar, or pitch, spread on calico, 

 linen, or leather. 



Poultices are made of linseed meal, bran, or oatmeal, 

 stirred into boiling water until the fitting consistence is 

 reached ; or of carrots or turnips, either steamed or boiled. 

 Bread and starch make mild porous poultices for ab- 

 scesses; spent hops for light poultices. Apply in flannel 

 bag or folded flannel. 



Purgatives evacuate the bowels. They are usually clas- 

 sified as follows : Laxatives or Aperients — small doses of 

 oil, magnesia, sulphur and molasses, with fruit, roots, and 

 green vegetable food. Simple Purgatives — full doses of 

 oils, aloes, and the various species of rhamnus. Drastic 

 Purgatives — croton oil, colocynth, elaterium, gamboge, and 

 podophyllin. Hydragogues — elaterium, gamboge, croton 

 oil, &c, with large doses of the more active salines. 

 Cholagogues — calomel and other mercurial preparations, 

 aloes, jalap, podophyllin, and euonymin, for bile. Salines 

 —(See ' Salines/ page 36.) Purgatives and other irritants 

 should be used cautiously in the case of the horse. If 

 possible, the animal should be restricted to mash diet or 

 green food for 2-4 hours previous to taking a purgative. 



Refrigerants allay heat and thirst. Water, particles 

 of ice, acidulated drinks, mild mucilaginous fluids, allay 

 thirst and stimulate the secretion of saliva. 



