PART IV 

 POWDERED DRUGS 



CHAPTER I 

 A METHODS FOR IDENTIFICATION 



Vegetable drugs frequently, perhaps in the majority of cases, reach 

 the pharmacist in the form of powders, and it is necessary not only to 

 identify them, but to determine their quality in this form. The old and 

 laborious method of making powders in small quantities, by the pharmacist 

 in his own store, has been supplanted by the specialized industry of drug 

 milling. Thus it is that adulteration is made easier and its detection more 

 difficult. Formerly it was considered sufficient for identification of vege- 

 table drugs to describe gross characteristics, such as, color, odor, taste, 

 and such other characteristics as might be brought out by hand lens; 

 but this method is wholly inadequate, and a more detailed examination, 

 microscopical and chemical, now is required. The enforcement of the 

 drug and food laws will require workers skilled in microscopical technique. 



Pulverization and Powdering. Prerequisite to the microscopical 

 study of vegetable powders is a knowledge of the processes of pulverization 

 and drug mills, such as may be found in any well illustrated work on 

 pharmacy, and elements of plant anatomy. 



The degree of fineness of the powders is of first importance in micro- 

 scopical examinations. Coarse powders can not be used and if they are 

 too fine the fragmentary tissues and products are too small to be recog- 

 nized. These degrees of fineness are represented by certain numbers. 

 A No. 80 powder, as defined by the U.S. P. VIII, for example, is one that 

 will pass through a sieve having 80 meshes to the inch. In the U.S. P. 

 IX No. 80 powder is defined as "Very fine powder, has a fineness in 

 diameter of particles less than 0.17 millimeters," and it is specified also 

 that the larger proportion of this must not pass through a sieve of lower 

 degree of fineness (See U.S. P. IX, Part II). To obtain the best results, 

 microscopically, powders may vary in fineness from No. 60, a fine powder, 

 to No. 80, a very fine powder. 



32' 497 



