On account of the clinical value of digitalis, the uncertainties in the results and untoward effects after administration have long been the subject of study, especially with a view toward their control or elimination. The attempts to secure derivatives, particularly of definite and uniform activity, are too numerous to discuss here. The fact that the tincture and the infusion are still more widely used than other preparations shows that the derivatives have not satisfied the demand of physicians. Our attempt has been to study these two preparations in such a manner as to control results of therapy by graphic methods, to learn so far as possible the promptitude with which effects can be secured, and the character of such effects.
All digitalis preparations used by us have been standardized according to a modification of the cat method of Hatcher. In relation to digitalis dosage Eggleston1 defines the "cat unit" of
WHITE SM, MORRIS RE. THE EGGLESTON METHOD OF ADMINISTERING DIGITALISWITH SOME NOTES ON DIGITALIS LUTEA. Arch Intern Med (Chic). 1918;XXI(6):740–778. doi:10.1001/archinte.1918.00090110037003