CHAPTER IV 



CAUSES MODIFYING THE CHARACTERISTICS OF VEGETABLE 



POWDERS 



Different drug samples of the same kind vary greatly as to the 

 gross characteristics. In many instances the deviations from the 

 normal or type specimen are so great that the identity of the drug is not 

 readily recognized. It is, therefore, of prime importance to be cogni- 

 zant of the possible variations in the gross characters which a drug 

 may undergo. It is necessary to enter into a consideration of those 

 factors or influences which are capable of modifying vegetable drugs, 

 as time and manner of collecting, curing, packing, shipping and storing; 

 the influences of climatic conditions, of cultivation, the presence of 

 parasites, etc. If these factors are kept in mind, the student will 

 have little difficulty in determining whether or not a given drug is of 

 fair quality. 



A thorough knowledge of the normal drug is necessary in order to 

 recognize the deviations from the 'normal. A thorough knowledge 

 of the normal histology of a drug is necessary to a recognition of the 

 presence of attacking hyphal fungi, additions of foreign tissues and 

 tissue elements, etc. Naturally the factors which modify the char- 

 acteristics of crude vegetable drugs also effect the powders made 

 therefrom. 



I. NOEMAL VARIATIONS 



By normal variation is meant such differences in different samples 

 or specimens of the same vegetable drug as are the result of normal, 

 necessary or unavoidable influences due to time, place and environ- 

 ment. Variations in size and form of crude drugs are generally not 

 noticeable when such drugs are reduced to powder, and if the quality 

 is unaltered, there is no reason why small, broken and otherwise altered 

 crude drugs should not be used in the powdered form. 



There is, also, considerable variation in the color of different 

 specimens. Younger or comparatively immature plant parts are likely 

 to assume a darker color and to shrink considerably upon drying. There 

 are unavoidable variations in the manner of curing, packing and storing 

 which will cause slight differences in the color and other characteristics 

 of the drug. It would be an endless task to enumerate all of the pos- 



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