CHAPTER VIII 



KEYS TO THE STUDY AND IDENTIFICATION OF SIMPLE 

 POWDERED VEGETABLE DRUGS 



The two keys are supplementary to each other. Each key may, 

 however, be used alone as it is independently complete in itself. Since 

 the recognition of the identity of a vegetable powder is primarily 

 dependent upon a careful microscopical examination, it is evident 

 that the key based on the gross characteristics is of secondary value. 



The use of the keys will serve two very important purposes. It 

 compels careful macroscopical and microscopical examination of the 

 drugs and it establishes a uniform and logical sequence in the method 

 and manner of examination. The use of the keys as a means of identi- 

 fication of the drugs is largely incidental* As the student gains more 

 and more experience in the critical study and examination of the 

 vegetable drugs listed in the keys, the keys lose more and more in 

 primary value and significance. 



I. KEY BASED UPON THE ORGANOLEPTIC TESTS. 

 MACROANALYTICAL KEY 



This key will prove an aid to the study and identification of powders 

 by those who are not in possession of a compound microscope. It will 

 be noted that the major divisions or groupings are based on color and 

 for that reason the key is somewhat defective or confusing, because 

 of the variation in colors, as has been explained elsewhere, and also 

 because the powders fade quite rapidly, even if kept well in the dark. 

 Basing the primary or major grouping on color differences is, however, 

 wholly consistent because this character is, as a rule, striking and is 

 the very first to be observed. It should also be borne in mind that 

 the odors and tastes cited refer to crude drugs. The process of powder- 

 ing does not change the taste and odor qualitatively, but quantitatively 

 these properties lessen considerably with tune. The following sugges- 

 tions may prove useful. If the odor is very weak, it may be concluded 

 that the powder is old, or that it may be adulterated with some odorless 

 substance. If the taste is abnormally weak, the addition of some 

 tasteless substance may be suspected. In comparatively rare in- 



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