Page:Popular Science Monthly Volume 6.djvu/781

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imity to the sun, and the writer had the satisfaction of watching the delicate, silvery ring inclosing her disk, even when the planet was only the sun's semi-diameter from his limb. This was at 4 p. m., or less than five hours before the beginning of the transit. The ring was brightest on the side toward the sun—the crescent proper. On the opposide side the thread of light was duller and of a slightly yellowish tinge. On the northern limb of the planet, some 60° or 80° from the point opposite the sun, the ring for a small space was fainter and apparently narrower than elsewhere. A similar appearance was observed on the same limb in 1866. The morning after the transit the sky was slightly hazy, and the planet could not be found. On the day following (the 10th) the crescent, extending to more than three-quarters of a circle, was seen with beautiful distinctness in the 9-inch equatorial, and on this and two subsequent days measurements were taken with the filar micrometer for the purpose of determining the extent of the cusps, and consequently the horizontal refraction of the atmosphere of the planet. These observations give a mean of 44'.5 as the horizontal refraction of Venus's atmosphere, or about one-quarter greater than that of the earth's. Six measurements of the diameter of the planet on the 10th give 63".1. Twenty-four on the 11th give 63".'75."


Blondeau on the Causes of Disease.—In the Moniteur Scientifique for November there is a very ingenious essay, by Dr. C. Blondeau, on the causes of disease, in which the author endeavors to show that morbid states are always the result of disordered cellular function. His argument is substantially as follows: The cell exists before the organized being, virtually includes it, and survives it after the play of its organs has been arrested. Hence, in order to understand the phenomena of the organization, we must study the cell which, when its functions are not disordered, is the primary cause of life and motion, but, when they are interfered with, of death. During life, every thing depends on the cell—when the animal respires, the cell acts the chief part in that function; when a muscle contracts, it is the muscular element, the cell, that feels the action of heat and causes the muscle to move. The same is to be said of nervous and glandular action. In a word, the life of the organism is simply the resultant of the life of the cells, their individual existence being coördinated to subserve a perfectly definite object. When this coördination is interfered with, we have disease. And hence, if we would reestablish the equilibrium, we must remove the obstacles which hinder the cell in the discharge of its functions; but to this end we must understand the nature of the agents which so interfere with its functions. These agents are all the poisons, whether organic or inorganic—whether viruses or mineral substances. The remedies to be employed, therefore, are counter-poisons, also derived from these two kingdoms. Innocuous viruses introduced into the animal economy may neutralize the dangerous effects of those which are toxic, just as certain mineral salts may destroy the disease-germ without endangering the life of the patient. Thus the germ of small-pox is neutralized by vaccine virus, and the syphilitic virus by the salts of mercury.

When it has been demonstrated that disease is the result of disordered cell-secretion, then medicine will rest upon a scientific basis. But, so long as we persist in regarding the human body as a mechanism set in motion by the same forces which act upon inorganic substances, we shall never be able, says the author, to explain the action of poisons on the organism. Until it is admitted that the blood is, for the most part, composed of organized living cells, that these cells act the principal part in forming and maintaining all our organs, and that they may undergo modifications which lead to serious maladies, we shall never be able to trace the disturbances occurring in the economy to any certain and definite cause, or to discover the proper remedies.


Tree-Planting in Towns.—The American Garden makes an earnest plea for the planting of trees in the streets of cities, as a sanitary measure. Growing plants assimilate the carbon of carbonic acid, discharging its oxygen into the atmosphere. The respiration of men and animals and the consumption of fuel load the atmosphere