Excerpt from Collected Papers From the Research Laboratory, Parke, Davis and Co., Detroit, Mich., 1919, Vol. 6 The method adopted for the assay of the digitalis series of heart tonics is that known as the one - hour frog heart or the mini mum systolic dose (m. S. D.) method. In a review of the various methods in use Edmunds and Hale (3) eliminated most of them as illogical or inaccurate. These authors found little reason for choice between the one mentioned above and another known as the minimum lethal dose (m. L. D.) method.1 Their preference inclined toward the former on the basis of cost and time. This method leaves much to be desired in regard to accuracy and dependability, since if one economizes either in time or in material it is usually at the expense of accuracy. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.