Materia medica is the name given to the collection of substances used in medicine; Pharmacy is the science of preparing medicine; Therapeutics is the science of applying medicine to the curing of disease. These branches, related and mutually dependent, are classified under the general head Pharmacology, or the science of drugs.
"Science professes to teach what is already known or may be learned in the forms of exact observation, precise definition, fixed terminology, classified arrangement and rational explanation." This science, therefore, embraces in classified forms Materia Medica, or the substance employed in medicine; Pharmacy, or the preparation of medicine; and Therapeutics, or the application of medicine to the cure of disease. Art is the application of science to practical purposes.
Physicians practice the art of therapeutics, or, in other words, put in practical application the knowledge of applying medicine. Pharmacists practice the art of pharmacy, or, in other words, put