VI PREFACE 



Since a correct knowledge of the structural relations of the plant- 

 parts to one another can scarcely be gained without some knowledge 

 of their uses in the economy of the plant, it follows that at least the 

 elementary facts of plant-physiology must be considered in connection 

 with its anatomy. 



The parts of plants which are used as drugs may come to us either 

 in their entire condition or in such large fragments as to be capable 

 of examination with the naked eye, or in the crushed or powdered 

 condition, when their examination requires the aid of the compound 

 microscope. Even in the case of the whole drug, the examination will 

 frequently call for the aid of the microscope in determining difficult 

 questions of identity or quality. 



Commercial Pharmacognosy may be defined as the application of 

 pharmacognosy to ordinary commercial operations. It includes the 

 examination of crude drugs by growers, collectors, traders, brokers, 

 importers, and ordinary purchasers for pharmaceutical purposes. 

 All such persons should be qualified to subject their drugs to the 

 most complete and minute examination, or should employ someone 

 who is so qualified; but, as a matter of fact, this is probably not 

 true in more than one case in a hundred, though happily this propor- 

 tion is steadily increasing. In all others, dependence is wholly upon 

 examinations made with the naked eye, or at most with a pocket lens. 

 The work on Commercial Pharmacognos}" will be designed for the use 

 of all such persons in their commercial operations with drugs. It will 

 deal with the commercial aspects of all drugs found in commerce, their 

 identity, varieties, grades, and qualities, their substitutes, adulterants, 

 and imperfections, their trade designations and relative values. 

 Although designed for use as a text-book, it will be especially valuable 

 in its commercial adaptations. 



In view of the totally different methods of examination involved, 

 and the apparatus and other facilities required, the subjects of 

 vegetable histology and of microscopical methods and technique are 

 omitted from the present work, its object being to teach the student 

 all that it is possible for him to do in the examination of drugs with 

 the naked eye or with the pocket lens. 



H. H. R. 



