46 POWDERED VEGETABLE DRUGS 



sible normal variations in form, size, color, odor and taste. We can 

 only call the student's attention to their existence, and urge upon him 

 the necessity of a careful study of the drug in order that he may 

 recognize these slight normal variations and distinguish them from 

 those of a more objectionable character. 



The student must also keep in mind the manner in which the 

 drug is prepared for the market. Some roots and rhizomes, as sarsa- 

 parilla. curcuma, jalapa, are exposed to high temperatures, which 

 converts some of the starch into paste and causes the drug to become 

 glossy, brittle and darker in color. The smoky (creosote) odor of 

 jalapa is due to the fact that the tubers are dried over an open fire. 

 Some rhizomes, roots and barks are partially or wholly peeled. All of 

 these differences in crude drugs modify more or less the appearance 

 of the powder, and this should be kept in mind in examining powders 

 macroscopically as well as microscopically. 



II. PARASITES 



One of the troubles of the practicing pharmacist is caused by the 

 various vegetable and animal pests which infest vegetable drugs. Some 

 of these parasites attack the drug yielding plants themselves (aphis), 

 but the majority of them work their destructive influences after the 

 drug has been gathered, dried and stored. Their presence greatly 

 modifies the appearance and value of drugs; and it is, therefore, of 

 great importance to be able to recognize the parasites or the effects 

 which they produce. Suggestions on the methods employed to de- 

 stroy them or to prevent their occurrence will be valuable. 



Strictly speaking, "parasites" is a misnomer, since the pests 

 referred to attack dead tissues, and are, hence, saprophytic in their 

 habits instead of parasitic; but since they are quite universally desig- 

 nated as parasites we shall retain that term in its older, though more 

 inaccurate application. 



1. THE VEGETABLE PARASITES 



The vegetable parasites which are found in and upon the various 

 vegetable drugs belong to the lower forms of plant life, as bacteria, 

 hyphal fungi and lichens. Some are present before the drug is col- 

 lected, as the lichens, less rarely also the hyphal fungi, but by far the 

 more objectionable species develop in and upon the drug after it is 

 ready for the market. All external plant parts or tissues are exposed 

 to the presence of a multitude of lower organisms, both plant and 

 animal, and many of these are normally present. For instance, a. 



