DRUGS OF VEGETABLE ORIGIN WITH ORGANIC 

 STRUCTURE. 



POWDERED SUBSTANCES. 



STARCHES. 



Starch is one of the most widely distributed of plant 

 proflucts, being found in some of its many forms or 

 modifications in nearly all families of the plant world. 



For the pharmacognocist a knowledge of the starches 

 is one of the most useful helps in the examination of drug 

 and food products. It is for him essential to know the 

 more common starches, and in the official drugs so many 

 of the starch forms are so constant that they are diag- 

 nostic. The starches of the various roots and rhizomes 

 will be noted under their appropriate heads, and it here 

 remains to note some of the more important starches used 

 as such. 



Starch for present purposes consists of small grains, 

 irregular in shape, possessing certain characteristics. 

 The intimate structure of these grains is a matter still 

 in controversy. 



For the present the starch grain is supposed to have 

 commenced at some definite point, spoken of in technical 

 language as the "hilum," About the hilum the starch 

 grain has grown up — how, we do not venture to assert — 

 until it comes U> prjssess a more or less definite shape and 

 size. The points in morphology to be noted are : shape, 

 whether the grains are bounded by rounderl or angular 

 surfaces; size; grouping, whether the grains are single 

 (simple) or arranged in groups (compound); presence 

 or absence of a hilum; position of the hilum, in the 

 centre, centric, or to one side, eccentric; shape of the 



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