Class I. - The Digitalis group, decreasing the frequency and increasing the force of the beat of the heart:

Digitalis, Strophanthus. Convallaria, Squill, Scoparius, Erythrophloeum, and Adonidin.

Class II. - The Aconite group, decreasing the frequency and force of the beat of the heart:

Aconite, Veratrum Viride, Veratrina.

Class III. - The Cactus group, increasing the frequency and force of the beat of the heart:

Cactus Grandiflorus.