RT Journal
A1 Lewis L
T1 THe potency of digitalis standardized according to u. s. p. xi
JF Journal of the American Medical Association
JO Journal of the American Medical Association
YR 1939
FD March 25
VO 112
IS 12
SP 1181
OP 1181
DO 10.1001/jama.1939.02800120066024
UL http://dx.doi.org/10.1001/jama.1939.02800120066024
AB To the Editor:— 
    The confusion concerning digitalis standardization is illustrated by a comparison of the opinions of two eminent authorities printed within a period of three weeks in The Journal.On Dec. 17, 1938, in "The Treatment of Cardiac Irregularities," George Fahr (page 2269, footnote 5) states: "At present digitalis is standardized according to the U. S. P. XI so that 0.65 cc. of the tincture or 0.065 Gm. (1 grain) of the powdered leaf is 1 Hatcher-Brody cat unit. In the previous editions of the U. S. Pharmacopeia 1 cc. of tincture or 0.1 Gm. of the powdered leaf contained 1 cat unit. One-tenth gram (1 1/2 grains) of the standard U. S. P. XI powder is equivalent to 1.6 Hatcher-Brody cat unit."On January 7, in "Drug Therapy in Coronary Disease" Harry Gold (page 5) states: "A satisfactory dosage in the average case of auricular fibrillation or heart