Elsewhere in this issue (Correspondence, p. 2093) appears a communication from the chairman of the Subcommittee on Biological Assays of the United States Pharmacopeia calling attention to the changes in strength and in method of assay of the digitalis preparations of the next revision of the United States Pharmacopeia. Important to the physician is recognition of these changes and understanding of their significance.
Justification for standardization of medicines lies in the facilitation of the interchange of experience. In successive revisions of the United States Pharmacopeia in past decades certain potent drug preparations have been made to conform to international practice. In the revision now current, the eleventh, effective since June 1, 1936, the strengths of powdered digitalis and tincture of digitalis have been adjusted to conform to the standards of the League of Nations. Those responsible for this decision knew that an increase in the strength of digitalis in use