PREFACE 



This volume, which is a condensed but fairly complete introduction 

 to botany, and is suitable as a text-book for academic or collegiate 

 students, has been written with special reference to the needs of the 

 first year student of pharmacy, as a preparation for his second year 

 work in pharmacognosy. It may, therefore, be regarded as an intro- 

 duction to pharmacognosy, as well as to general botany. It will be 

 followed by a companion volume on Commercial Pharmacognosy. 



Pharmacognosy may be defined as the art of identifying, valuing, 

 and selecting drugs of vegetable and animal origin. It is, therefore, 

 not a distinct science, although various sciences may be employed in 

 its practice. In such operations as taking specific gravity, making 

 microscopical measurements and determining the characters of crystals, 

 physics is utilized. In making qualitative tests of identity and purity 

 and determining the percentages of constituents, chemistry is involved. 

 In determining the structural characters of plant and animal bodies, 

 botanical and zoological knowledge is necessary. In determining the 

 value of drugs of which the purity and strength cannot be estimated 

 by any of these methods, we may have recourse to physiological tests 

 on animals, or pharmaco-dynamics. 



It is thus apparent that the entire field of pharmacognosy is very 

 broad and that its complete working involves varied classes of labora- 

 tory operations. The extent and complexity of detail that have 

 become necessary in these operations have required their consideration 

 in separate departments of the pharmaceutical curriculum, so that such 

 branches as physical and chemical testing and pharmaceutical assaying 

 have been established. 



The number of drugs of animal origin in general use has become so 

 small that the study of zoology is no longer deemed essential, and it is 

 left to botany to contribute by far the greater portion of the instruction 

 now deemed essential as a preparation for the study of pharmacognosy. 

 Manifestly, a knowledge of structural botany is the only scientific 

 basis for the examination of the plant body. 



