CHAPTER I. 

 DEFINITIONS, WEIGHTS, AND MEASURES. 



For the purpose of curing disease the medical practitioner makes use 

 of many substances of animal, vegetable and mineral origin, as well as an 

 increasing number of substances prepared by the chemist synthetically. 

 The substances that are so used are known inclusively and collectively as 

 the "MATERIA MEDICA. " Any substance administered to a patient for 

 the purpose of curing or alleviating disease may be termed a "DRUG." 

 But not all substances that have been used by man as medicines are still 

 in common use in civilized lands to-day, and many of the newer remedies, 

 though highly lauded by their discoverers have not, and in many cases 

 will not prove to be of sufficient merit to come into common favour. In 

 consequence of this and as a guide to the physician and especially as an 

 aid to his allies the pharmacists, most modern governments have caused 

 to be prepared and published, books known as ' ' PHARMACOPOEIAS . " Such 

 a pharmacopoeia contains the correct legal or "official" names both in 

 Latin and in the vulgar tongue of such substances of the materia medica as 

 are judged by those who compile the pharmacopoeia to be in common use 

 in the country and to be of value to the physician. Further for the guid- 

 ance of those who purchase crude drugs and prepare them for the patient's 

 use the pharmacopoeia contains accurate descriptions of the physical and 

 chemical characteristics of the drugs and of the methods by which they are 

 prepared for administration. The term "official" may be applied only to 

 such drugs, preparations, methods and doses as are included in the British 

 Pharmacopoeia. This term must be carefully distinguished from the 

 more inclusive term "officinal" which may be applied to any drug, etc., 

 whether included in the Pharmacopoeia or not, so long as it is in common 

 use. 



" PHARMACOGNOSY " is the science of the source and characteristics of 

 the substances of the materia medica. This includes a knowledge of the 

 natural history of all the plant, animal, and mineral products in the materia 

 medica, as well as a knowledge of the methods of chemical preparation of 

 those drugs that are produced synthetically, and a knowledge of the chem- 

 ical and physical characteristics of all drugs. Some of the more important 

 facts of the pharmacognosy of the drugs reviewed in this book will be re- 

 ferred to when they are individually considered. 



"PHARMACY" is the art of the proper preparation of the substances of 

 the materia medica for use (exhibition) and administration as medicines. 

 This science may be divided into three branches. Firstly, Chemical 



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