4 
of digitalis, strophanthus and ergot from supposedly reliable 
sources and found that they varied in strength in the ratio 
of | to 4, 
Any number of instances could be cited to show how 
variable and unreliable are fluid extracts and tinctures made 
-according to old and imperfect methods, and which have 
not been subjected to a rigid examination to determine their 
values as medicinal agents. 
Long ago we became convinced that the only way to 
insure, in a given product, exact and uniform medicinal 
action was to standardize it—that is, to adjust it to a 
definite alkaloidal or other standard by systematic assay. 
: We entered the field of standardization thirty years ago; 
we were the pioneers—the first to abandon the uncertain 
methods in vogue and to make use of accurate processes— 
the first to prove the activity of drug products and to 
_ systematically measure that activity. 
To one product after another, therefore, we began to 
: apply certain chemical tests to assure ourselves of their 
potency, and proceeded, scientifically, to adjust them to a 
uniform standard of strength—so that each dose might 
always be relied upon, barring idiosyncrasy in the patient, 
eee to exert the same measure of therapeutic effect. 
- Fifteen yee ago we oa limitations of chemical 
