GENERAL PRINCIPLES AND RULES xxvii 



special methods which apply to individual drugs, showing indirectly 

 their quality. 



(3) Microscopical methods of valuation may oftentimes be 

 employed when other methods fail, as, for example, when foreign 

 starches are added to starchy products, as the cereals and spices. 

 Microchemical reactions may also be depended upon in some instances 

 to indicate the value of a drug, as in strophanthus, where the quality 

 of the drug appears to bear a direct relation to the number of seeds 

 giving a green coloration with sulphuric acid. The separation of the 

 salts of the alkaloids in hydrastis on the addition of sulphuric acid is 

 also of value in determining the quality of this drug. 



(4) Biological methods involve the consideration of the effects 

 of drugs upon animals or plants. They may be conveniently grouped 

 as follows: 1. Effects or influence upon animals, including (a) those 

 dependent upon the perceptions or senses of the experimenter or 

 tester, as color, taste and odor; (6) those which are physiological or 

 pathological. These are usually determined by experiments upon 

 insects, frogs, rabbits, guinea pigs, fowls, cats, dogs, fish and even 

 upon man. 2. The effect or influence produced upon plants by drugs, 

 or solutions of their active principles. For experiments of this kind 

 seedlings are usually employed 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. 1 Some of the lower plants 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. 



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 identifi- 

 cation 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, such as are used by printers, the top being cov- 

 ered with glass which can be removed. The glass can be kept in 

 place by means of long, broad-headed tacks or can be fastened per- 

 manently by means of hinges. The frames may be hung on the wall 

 or held by means of molding. 



The Study of Drugs may be pursued from a number of viewpoints. 

 In an artificial system they may be grouped according to the parts of 

 plants from which they are derived, as roots, rhizomes, leaves, etc. 

 This method has much to commend it in practice, but unfortunately 

 the form of the commercial article is not such that it is always pos- 



1 Kraemer, "Assay of Drugs by means of Living Plants," Amer. Jour. Pharm., 

 1900, p. 472; Saylor, Ibid., 1916, p. 8. 



