DECOCTIONS 709 



They preserve asepsis, support the sutures, and prevent or 

 diminish the consecutive oedema. They are also employed 

 with the object of ensuring asepsis of the operation area 

 prior to neurectomy, tenotomy, oophorectomy of the bitch 

 and cat, aspiration of bursal distensions, etc. Before 

 application, the hair is removed from skin of the region, 

 which is then washed and disinfected, and the compress is 

 kept in place until the patient is in position for operation. 



DECOCTIONS 



Decoctions are solutions prepared by boiling the drug in 

 distilled water. To ensure perfect solution, the substance 

 is bruised or cut into small pieces, and boiled in a glass or 

 earthenware vessel for five to ten minutes. Any insoluble 

 residue is subsequently separated by straining through 

 muslin or calico, or by allowing the solution to settle, and 

 pouring off the supernatant fluid. Decoctions intended to 

 be kept beyond a week or two should be preserved by 

 adding a little spirit or about one part of benzoic acid to 

 200 of decoction. 



DOSES AND THEIR ADMINISTRATION 



The dose, or quantity of the medicine used, affects the 

 degree, and sometimes also the nature of the action pro- 

 duced. Thus, small doses of most salts of potassium, 

 sodium, and magnesium are diuretic, while larger quan- 

 tities are purgative. Aloes, in small quantity, is tonic, 

 and in large, purgative. Alcohol and opium are examples 

 of medicines in which variation in dose produces difference 

 in effect. With topical remedies, an increase of the time 

 during which the drug is applied is generally equivalent to 

 an increase of dose, as illustrated in the case of mustard, 

 cantharides, and concentrated acids. 



The period during which a drug remains in the body 

 determines in like manner its activity. Hence increased 

 action results from rapid absorption and prolonged retention 

 within the body, while diminished action results from tardy 

 absorption and quick excretion. Where prompt and full 



