xxviii INTRODUCTORY 



sible to determine whether it should be placed among roots or rhi- 

 zomes, leaves or herbs, etc. A second system of arranging drugs is 

 according to their important constituents. This may seem to many 

 very desirable and enable us to develop a scientific pharmacognosy 

 to be used as a basis for a rational pharmacology. Unfortunately 

 our knowledge of the chemical constituents of drugs is very meager, 

 and in those drugs which have been investigated there may be present 

 a number of principles, each one of which serves a useful purpose. A 

 third method is to consider the plants yielding drugs according to 

 their natural relationship. With our knowledge of the morphology, 

 including both organography and the inner structure of such a large 

 number of plants, it would seem that this would furnish the best 

 system for practical pharmacognosy and be the most stimulating to 

 the investigator. In a large number of families we find there are 

 certain morphological characters that are more or less distinctive 

 for each. The Composite, for instance, are distinguished by their 

 containing inulin. The Labiatae have not only square stems and 

 bilabiate calyces and corollas, but typical 8-celled glandular hairs. 

 Furthermore, two or more drugs are not infrequently derived from a 

 single plant, and the reason for this can be better considered in con- 

 nection with the products derived from a single plant than if they are 

 placed in widely divergent groups. After many years of experience 

 as a teacher and trying out the several methods in class work I 

 have come to the conclusion that the natural classification of plants 

 is not only the most systematic, but the most effective in practice. 



Literature. Tschirch, Handbuch der Pharmakognosie, 1912. 



Power, The Aims and Developments of Phytochemical Research. 

 Am. Jour. Pharm., 1917, 89, p. 97. 



Lloyd, Plant Textures, Amer. Jour. Pharm., 1917, 89, p. 387. 



Ewing and Stanford, Botanicals of the Blue Ridge. Jour. A. Ph. 

 A., 1919, 1 p. 169. 



Taylor, The Pharmaceutical Chemist and the Scope of his Work. 

 Jour. Indus. Eng Chem., 1919, 11, p. 239. 



Alsberg, Viehoever and Ewing. Some of the Effects of the War 

 upon Crude Drug Importations. Jour. A. Ph. A., 1919, 8, p. 459. 



Beal, George D., Chemistry's Opportunity in Pharmaceutical 

 Research. Jour. A. Ph. A., 1919, 8, p. 260. 



Kebler, Fraudulent Advertising. Jour. A. Ph. A., 1919, 8, p. 201. 



Power. The Distribution and Characters of some of the odorous 

 Principles of Plants. Jour. Indus. Eng. Chem., 1919, 11, p. 344. 



