Among the few really indispensable drugs which we have, digitalis would be placed in the very front rank by most medical men, and this is true in spite of the fact that its use is attended by certain disadvantages, and that these disadvantages are not regularly to be estimated, owing to the complex nature of the constituents of the drug, and the varying proportions in which these are present in the crude leaves. The various alkaloids and glucosids, obtained from the crude drug, have not been widely known because of technical difficulties in preparation, and have not made their way into general favor. Moreover, the exceeding smallness of the dose, and the considerable risk of cumulative effect have added to the distrust with which most practitioners have looked on these drugs. But the evident gain from the use of a definite active principle is so great that determined efforts have