26 DISEASES OF CATTLE, SHEEP, GOATS, ETC. 



Medicines act both locally and generally. The local effect of a 

 -nedicine is produced when the medicine is applied directly to a part, 

 and when the effect is limited to the part to which it is applied. 

 The general effect of a drug is produced only when the drug enters 

 the circulation; some medicines may produce such an effect when 

 locally applied as a result of absorption through the tissues. Med- 

 icines also act physiologically and therapeutically. The physiolog- 

 ical action 'is said to be gotten when the drug produces the same 

 effect in health as in disease. When such actions are exerted in the 

 cure of disease they are termed therapeutic or curative actions. Med- 

 icines, too, have a certain affinity for certain organs or sets of or- 

 gans ; for example, aloes exerts its influence upon the digestive tracts, 

 nux vomica upon the nervous system, aconite upon the heart, spirits 

 of nitrous ether upon the kidneys, etc. Just why a medicine affects 

 one organ more than another has not been satisfactorily explained ; 

 that medicines do have such an affinity, however, has been thor- 

 oughly proven. 



Medicines are said to cure disease in three ways: 1st, by allo- 

 pathy, whereby effects are produced which overcome the disease; 

 2d, by antipathy, whereby medicines overcome disease by more pow- 

 erful and antagonistic force; 3d, by homoeopathy. The advocates 

 of this theory claim to cure disease by the administration in small 

 doses of such medicines that in large doses would produce symp- 

 toms similar to the disease to be cured. This theory does not meet 

 with as general favor as the other two theories. 



Antiseptics are agents which destroy bacteria and arrest putre- 

 faction. They prevent suppuration in wounds, thereby hastening 

 the healing process. Examples, bi-chloride of mercury in solution 

 of 1-1000, lysol, carbolic acid, creolin, etc. 



Disinfectants are agents which destroy the specific poisons, 

 bacteria, of contagious diseases. They are used to disinfect build? 

 ings in which diseased animals have been kept, for cleansing 

 wounds, etc. The same class of drugs are used as in the above. 



Deodorizers are agents which destroy smells. They do so by 

 disguising or destroying the cause of the odor. Permanganate of 

 potash is the best example of this class of drugs. 



Counter-irritants are those agents which, when applied to the 

 surface of the body, counteract or allay deeper seated inflamma- 

 tions, or cause the absorption of abnormal enlargements to which 

 they are applied. In acute inflammatory attacks they allay the 

 congestion through reflex action. They may be used beneficially 

 in bronchitis, Dneumonia, and in the secondary stages of inflamed 

 joints, counter-irritants stimulate the circulation and hasten resolu- 

 tion. 



Astringents contract the living tissue. They may also produce 

 their effect by coagulating or precipitating albumen. They are used 

 to check excessive diarrhoea and to arrest hemorrhage. Acids, salts 

 of iron, chalk and tannic acid are examples. 



Demulcents and emollients soothe, soften, relax and ensheathe 

 the parts with which they come in contact. This action is entirely 



