SCOPE AND PROBLEMS xvii 



tion at present, yet the interest in this method of analysis is growing 

 to such an extent that we may expect before long that the crystal- 

 lographic methods of analysis will play quite as important a part in 

 the work of the pharmacognocist as the anatomical or histological 

 methods have up until this time. 



Problems of Pharmacognosy. Pharmacognosy has for its object 

 the study of drugs and the plants yielding them. The main object 

 is not only to determine the identity of the drug and its origin, but 

 the study of its constituents and the factors influencing their varia- 

 tion in the living plant as well as after collection. In the pursuit 

 of pharmacognosy we examine drugs which for the most part consist 

 of broken fragments, and from these pieces, frequently microscopic 

 in size, the plants from which they are derived must be determined. 

 Again, particles which resemble each other or are obtained from 

 very closely related species must be separated. Parts of other plants 

 growing with them in the soil must be distinguished and standards 

 established showing how much of this extraneous material is per- 

 missible, and these standards must be so framed that drugs collected 

 at widely separated points will be of uniform quality and efficiency. 



The problems of pharmacognosy take us at once into the field 

 where the origin of the drugs can be studied at first hand. A second 

 phase of the subject are the studies of pure morphology dealing with 

 the development of certain structures as the stipes in cubeb, or the 

 origin of tissues in seeds, and scars or markings in roots and rhizomes. 

 The difference in constituents of different parts of the same plant, as 

 the oils in the leaves and bark of cinnamon or difference in the propor- 

 tion of alkaloids in the different kinds of cinchona, offers a most fertile 

 opportunity for the application of physiological studies. Further- 

 more, when we approach the subject of the cultivation of medicinal 

 plants we are confronted with the problems of hybridization and 

 mutation. We may further expect those who have had special 

 training in the literature and language are likely to become interested 

 in the historical study of drugs and in the nomenclature employed in 

 designating them in commerce. In the historical study of drugs 

 such phases are considered as the origin of their introduction into 

 medicine, the dissemination of information concerning their uses 

 among other nations, the official recognition by some, of the more 

 important pharmacopoeias, and finally the facts regarding their 

 real usefulness as supplied by modern pharmacological investigations 

 and clinical experience. 



The study of synonyms is one of the most important departments 

 of pharmacognosy. While there have been some attempts to treat 



