PRACTICAL VETERINARY PHARMA- 

 COLOGY AND THERAPEUTICS 



CHAPTER I 

 DEFINITIONS 



The terms Materia Medica, Pharmacognosy, Pharmacographia, 

 Pharmacology and Pharmaco-dynamics used in the same general way 

 have the same meaning. They may be broadly defined to cover all 

 scientific knowledge concerning drugs. If it is desired to limit the 

 meaning of the terms more specifically, they may be differentiated as 

 follows : 



1. Materia Medica (Pharmacographia) deals with the physical 

 and chemical properties of drugs, their sources, history, anatomy, 

 pharmaceutic preparations and doses. 



(a) Organic Materia Medica was a term formerly used to desig- 

 nate drugs obtained from the vegetable kingdom. 



(b) Inorganic Materia Medica was likewise used to designate 

 those derived from the mineral kingdom. 



2. Pharmacology (Pharmaco-dynamics) treats of the action of 

 drugs upon living organisms. 



3. Pharmacy is the science and art of preparing, compounding 

 and dispensing drugs. It includes metrology (Weights and Meas- 

 ures), manufacture and dispensing. 



4. Toxicology is the science which deals with the detection of 

 poisons, their symptoms and treatment or antidotes. 



5. Therapeutics is that subject which deals with the methods 

 used in the cure or alleviation of disease. In other words it is the 

 application of pharmacology or materia medica and other sciences to 

 the treatment of disease. 



A drug is any substance other than a food stuff or mechanical 

 agent that produces change in a living organisni. _ If used in doses 

 suitable to produce beneficial effects, it is a Medicine, but if the dose 

 is sufficiently large to produce harmful effects, it is a Poison. 



SOURCE AND COMPOSITION OP DRUGS 



Drugs are obtained from both organic and inorganic substances. 

 The vegetable and biological preparations are obtained from the 

 former while the various metals and their salts, the composition of 



