MECHANISM OF THE HEART.

New Zealand Herald, Volume XXV, Issue 9130, 11 August 1888, Page 2 (Supplement)

MECHANISM OF THE HEART.

WORKING OF THE ORGAN WHOSE

STOPPAGE MEANS DEATH. In the human subject the average rapidity of the cordiac pulsation of an adult male is about seventy beats per minute. These beats arc more frequent, as a rule, in young children and in women, and there are variations within certain limits in particular persons, owing to peculiarities of organisation. It would not necessarily be an aonormal sign to find in some particular individual.* the habitual frequency of the hearts action from sixty to sixty-live or from seventy-live to eighty per minute. As a rule the heart's action is slower and more powerful in fully developed and muscular organisations, and more rapid and feebler in those of slighter form. In animals the range is from twenty-live to forty-live in the cold-blooded, and fifty upward in the - blooded animals, except in the ease of a horse, which lias a very slow heart beat, only forty strokes a minute. The pulsations of men and all animals differ with the sea level also. The work of a healthy human heart has been shown to equal the feat of raising live tons four hundredweight one foot per hour, or 12.") tons in twenty-four hours. The excess of this work under alcohol in varying quantities is often very great. A curious calculation has been made by Dr. Richardson. giving the work of the heart in mileage. Presuming that the blood was thrown out of the heart at each pulsation in the proportion of sixty-nine strokes per minute and at the assumed force of nine feet, the mileage of the blood through the body might be taken at _U7 yards per minute, 7 miles per hour, 1(»S miles per day, b1.0'20 miles per year, or o, IoO.SSO miles in a lifetime of SI years. The number of beats of the heart in the same long life would reach the grand total of 'J,Mi1',770,000. — Medical World.