Gray Hair

The sedentary, the studious, the debilitated, and the sickly, are, with very few exceptions, those who are earliest visited with gray hair. The agricultural laborer, the seaman, and all whose employment consists of or involves exercise in the open air, are those whose hair latest affords signs that the last process has commenced, that the fluids have begun to be absorbed, and the textures dried up and withered. All whose employment renders much sitting necessary, and little or no exercise possible; all who, from whatever cause, have least determination; particularly if toward the head, are the persons most liable to carry gray heirs. It is well known that mental emotions and violent passions have, in a night, made the hair gray. These instances are in the same way to be understood and explained. They are owing to the increased determination of the blood stimulating the absorbents into preternatural activity, and causing them to take up the coloring matter of the hair.

Human Pulsation

An ingenious author asserts that the length of a man's life may be estimated by the number of pulsations he has strength to perform. Thus, allowing seventy years for the common age of man, and sixty pulses in a minute for the usual measure of pulses in a temperate person, the number of pulsations in his whole life would amount to 2,207,520,000; but if, by intemperance or other causes, he forces his blood permanently into a more rapid movement, so as to give seventy-five pulses to the minute, the same number of pulses would be completed in fifty-six years; consequently shortening his life by fourteen years.

Influence Of Light Upon The Human Constitution

Dupuytren, the French physician, relates the case of a lady whose maladies had baffled the skill of several eminent practitioners. The lady resided in a dark room, into which the sun never shone, in one of the narrow streets of Paris. After a careful examination, Dupuytren was led to refer her complaints to the absence of light, and recommended her removal to a more cheerful situation. This change was followed by the most beneficial results, and all her complaints vanished. Sir James Wylie has given a remarkable instance of the influence of light. He states that the cases of disease on the dark side of a barrack at St. Petersburg have been uniformly, for many years, in the proportion of three to one to those on the side exposed to strong light. The experiments of Dr. Edwards are conclusive. He has shown that if tadpoles are nourished with proper food, and exposed to the constantly renewed contact of water (so that their beneficial respiration may be maintained), but are entirely deprived of light, their growth continues, but their metamorphosis into the condition of air-breathing animals is arrested, and they remain in the form of large tadpoles. Dr. Edwards also observes that persons who live in caves or cellars, or in very dark and narrow streets are apt to produce deformed children; and that men who work in mines are liable to disease, which can only be attributed to the withdrawal of the blessings of light.