Page:Popular Science Monthly Volume 40.djvu/841

Rh get the excess of poison oxidized; when, therefore, unconsciousness supervenes, we may say pretty confidently that the rapid circulation and the rapid breathing have not been sufficient to oxidize and neutralize the mass of poison which is being carried to the brain. So, again, in pneumonia the quickened breathing shows both the effort of Nature to make up for the loss of that part of the lung which is ineffective, and also the stimulus which the increased waste poison in the blood (increased owing to diminished lung capacity, and therefore diminished oxygen) exerts upon the respiratory machinery. So, again, when less blood is carried to the lungs, owing to the artery which leads from the heart to the lungs being partially blocked with a clot, the same effect is produced. Probably a somewhat similar condition arises after hard work, either in old age or in a feeble state of health. The tissue, not being in the firm condition of the tissue of a vigorous person accustomed to daily work, breaks down in large quantities, while at the same time the circulatory and respiratory machineries are no longer at their best, and therefore the oxidation is imperfect. On the next day the infirm man is poisoned by the unusual quantity of waste in the system, and feels discomfort in many parts of his body or limbs. So, also, the discomfort acutely felt by some persons during east winds probably arises from the poison that ought to have been got rid of by the skin, but, owing to the closing of the pores, has been thrown back into the system. So also with ordinary violent exercise. When we take violent exercise an unusual quantity of waste is thrown into the blood, requiring an unusual quantity of oxidation. Here also the waste stimulates the nerve-centers, increasing action of heart, and of respiratory muscles, so that the blood charged with waste and the air may come into quicker contact. The successful