Every time that the heart beats, a contraction of the spiral fibres takes place, and the blood is sent through the arteries by the force of the stroke, as water gushes through a syringe; and exactly at the same time an equal proportion is received from the veins. Thus at every pulse about two spoonfuls of blood are sent out from the human heart, through the arteries, and the same quantity is received through the veins. It is said that each ventricle of the heart will contain an ounce of blood. The heart contracts four thousand times in an hour, from which it appears that four thousand ounces, or two hundred and fifty pounds of blood pass through the heart every hour!—[From Parley’s Farewell.]
PETER PARLEY’S NEW STORIES.
[No. V.]
Don’t be too Positive.
There are many young persons who are very positive about things, when they are, after all, mistaken.
“There goes Jerry Smith,” says Philip.
“Where? I don’t see him,” says John.
“Why, there—yonder, at the top of the hill.”
“Oh—that ain’t Jerry Smith.”
“Why, yes it is.”