Page:Popular Science Monthly Volume 25.djvu/254

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have courage to kill a bird in hunting; but, in making experiments, I have no such scruples. Science has a right to invoke the sovereignty of the end."

What he has done, M. Pasteur regards as only the beginning of what is to be accomplished in the same line. "You will see," he has sometimes said, "how this will grow as it goes on. Oh, if I only had time!"



AMONG the subjects that claim the study of the sanitarian, there is none that has a closer relation to public health, and hence none more worthy of careful investigation, than the water we drink. Receiving it, as we do, from varied sources—from spring, well, brook, or river—its character varies greatly; and, while in its purity bringing with it refreshment and health, in a polluted condition it too often carries in its wake disease and death.

The study of sanitary science during the last few years has demonstrated beyond a doubt that many severe epidemics have arisen from the use of impure water, as the reading of Witthaus, Parkes, Buck, Flint, Pavy, or other writers on the subject, will clearly prove.

When we remember that water has greater solvent properties than any other liquid known, we can readily understand how it often becomes such a disease-spreading medium. Besides carrying with it vegetable and organic impurities in suspension, it dissolves many of those that are the most subtile and dangerous to the human organism. The dangers of drinking impure water may best be presented in a few quotations from well-known authorities.

Pavy, in "Food and Dietetics," says: "Water has much to answer for in the causation of disease. ... It" (polluted water) "is acknowledged to be one of the common causes of dysentery, and has been alleged, when derived from a marshy district, to be capable of inducing malarial fever and its concomitant, enlargement of the spleen. ... Typhoid has been frequently communicated through the medium of water. Milk, adulterated with polluted water, has been the cause of serious outbreaks of fever." Parkes, in his "Manual of Practical Hygiene," shows that the baneful effects of polluted water were known to the ancient Greeks. Hippocrates, who was born 460 b. c, asserts, "The spleens of those who drink the water of marshes become enlarged and hard." Parkes considers typhoid, cholera, scarlet fever, and diphtheria, and some forms of skin-disease, "likely to be propagated by means of water."

Polluted water that has been frozen, though improved by the freezing, does not become innocuous. "Ice and snow may be the