In what I have just said regarding the effect of blood-pressure on the heart I have spoken of the total work, including in it both the rapidity of pulsation and the amount of work done by each beat. This is, perhaps, fair enough; but at the same time we must not forget that there is a distinction between the total amount of work done and the nature of the individual contraction, either in the heart of tortoises or mammals, or in voluntary muscles. Both voluntary muscles and the heart tend to contract rapidly if they have little resistance to overcome. In patients suffering from anaemia and debility, where the blood-pressure is low and the resistance to the ventricular contractions is consequently small, they are apt to take place with great quickness, giving rise to a short flapping first sound and a short but unsustained apex-beat, while the patient complains of much palpitation. In such cases increased blood-pressure will tend to lessen the palpitation, and digitalis, which contracts the vessels, will be useful; iron also is serviceable by increasing the nutrition of the circulatory apparatus of the body generally. The low blood-pressure, however, while it increases the tendency to palpitation, is not the only factor, and is usually accompanied by a tendency to disturbance of the cardiac innervation, which is to be met by sedatives such as the bromides, or by remedies directed to the stomach or other organs from which the disturbing stimulus may proceed.