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portant of the arts. That part of pharmacy that relates 
to the identification, estimation, and selection of drugs is 
Pharmacognosy. Many methods have been resorted to 
in the history of medicine to secure or insure uniformity 
in the strength of medicinal preparations. For the state 
of perfection to which this art has now been brought, the 
world is chiefly indebted to the house of Parke, Davis & 
Company, of Detroit, and to George S. Davis, its manager, 
and Albert B. Lyons, its distinguished chemist. These 
pioneers, in the face of great opposition, devised a class of 
fluid extracts known as “‘Normal Liquids,” in which the 
amount and character of the drug used was so regulated 
that the preparation would always contain the same per- 
centage of active constituent, that is, always have the same 
medicinal strength. This method of manufacture has 
since been developed and perfected until it is now the 
basis of modern methods in medicine manufacture. It is 
unfortunate that there are some drugs of which the medi- 
cinal constituent cannot be determined. In such cases, 
this method is not applicable, and in some of them the 
method of physiological standardization is now resorted 
to. By this method, the medicine is tested by adminis- 
tering it to a standard animal and noting the degree of 
the effect produced. The method is by no means so definite 
and positive as that for chemical standardization above 
described, but it has sufficed to vastly improve the quality 
of some medicines of that class. 
The drugs in this Museum are classified primarily as to 
the part of the plant represented: (1) roots, rhizomes, 
bulbs, tubers, and other underground parts, (2) barks and 
woods, (3) leaves, (4) herbs and other plant-bodies, (5) 
flowers, (6) fruits, (7) seeds, (8) miscellaneous plant prod- 
ucts, such as exudations, juices, and trichomes. Each of 
these groups has a subordinate botanical sequence. 
