424 



BOTANY AND PHARMACOGNOSY. 



produced upon plants by drugs, or solutions of their active prin- 

 ciples. For experiments of this kind seedlings are usually em- 

 ployed and the effects are based upon the amount of growth of 

 the root of the plant in a given time when placed in the solution. 

 Some of the lower plants (p. 5) are also used in testing the 

 properties of chemicals, which may have a toxic action on the 

 protoplast or a plasmolytic action on the protoplasm (Fig. 55, //). 



Fig. 183. Case for drug specimens. 



Drug Collections. It is important that the student, phar- 

 macist and analyst possess a collection of typical drug specimens. 

 It is necessary in the study of drugs and also for purposes of 

 identification and comparison. Specimens may be kept in various 

 kinds of boxes and bottles, but one of the most satisfactory ways 

 is to keep them in type cases (Fig. 183) such as are used by 

 printers, the top being covered with glass which can be removed. 



