replace alcohol as a heart tonic. The thing necessary to encourage the heart's action is not merely relaxation of the peripheral vessels, but, as Winternitz has shown, increased activity of the peripheral circulation in the skin, muscles and elsewhere. Alcohol paralyzes the vasoconstrictors, and so dilates the small vessels and lessens the resistance of the heart action; but at the same time it lessens the activity of the nerve centres which control the heart, diminishes the power of the heart muscle, and lessens that rhythmical activity of the small vessels whereby the circulation is so efficiently aided at that portion of the blood circuit most remote from the heart. A continuous cold application applied to that portion of the chest overlying the heart stimulates the nerves controlling the walls of the vessels, and at the same time energizes the corresponding cardiac nerves. It is wise to remember that the vasoconstrictor nerves are one in kind with the excitor nerves of the heart, while the vasodilators are in like manner associated with the vagus. With this in mind, it is clear that while alcohol paralyzes the vasoconstrictors, it at the same time weakens the nerves which initiate and maintain the activity of the heart; while, on the other hand, cold excites to activity those nerves which produce the opposite effect.
"The apparent increase of strength which follows the administration of alcohol in cases of cardiac weakness is delusive. There is increased volume of the pulse for the reason that the small arteries and capillaries are dilated, but this apparent improvement in cardiac action is very evanescent. This is a natural result of the fact that while the heart is relieved momentarily by sudden dilation of the peripheral vessels, the accumulation of the blood in the venous system, through the loss of the normal activity of the peripheral heart, gradually raises the resistance by increasing the amount of blood which has to be pushed along in the venous system. This loss of the action of the peripheral heart more than counterbalances the temporary relief secured by the paralysis of the vasoconstrictors.
