“2d. That this morbific matter can be detected only by its specific action upon human subject, and can not be distinguished, either by chemical or microscopical analysis, even in the concentrated excreta, much less in water mixed with the excreta.
“3d. That, inasmuch as the organic matters of sewage are oxidized and destroyed with extreme slowness in running water, there is great probability that morbific matter will escape destruction and be conveyed to great distances in rivers and streams.”—(Rivers Pollution Commission, 1874.)
“Carbonates of calcium and lime produce temporary hardness; while sulphate of lime and calcium and salts of magnesium produce permanent hardness.
“Temporary hardness is objectionable for culinary and manufacturing purposes, and excessive hardness is productive of disease known as gravel. Magnesium salts are especially objectionable, because they cause diarrhœa and dyspepsia. Goitre, or swelling of the glands and cretinism, a kind of insanity, are charged to this impurity.
“Frequently, the water happens to be a little off color, especially after a heavy storm, and the consumers get an idea that the water is poisoned, and no amount of re-assuring will prove the reverse. Such cases occurred in New York City, once or twice, during the late war with the South. A little investigation will show the absurdity of such a thing.
“One-sixteenth of a grain of strychnine is necessary to poison a person. It would, therefore, require three and one-half tons of strychnine to have poisoned the Croton water effectually—a quantity not to be had in the world, and to procure it would take about three years.
“If arsenic was desirable, two grains for each person would be required, or 114 tons for the whole population of the city at that time. Living animals, when seen under the microscope, are very formidable in appearance and frightful in motion, yet they are not objectionable. They only inhabit very pure water. It sometimes happens, owing, perhaps, to some peculiarity of the season, that these little animals multiply to such an extent as to produce serious annoyance.
“It is stated that one-sixth of the deaths in Iceland are caused by little animals being taken into the system. Young leeches, contained in drinking water, sometimes fix themselves on the pharynx. In Algiers, 400 French soldiers were sick at one time from this cause.”—(From Prof. Foote’s lecture.)
CONTAMINATION OF WATER SUPPLY.
Boston water has become quite offensive from vegetable fermentation, some say, although others attribute it to dead fish, eels, and animal organisms, and, later, to a green moss. The water tastes, at times, like cucumbers. The present trouble is traced to the new “Sudbury” supply. The older source, Lake Cochituate, is, however, contaminated by drainage from the town of Natick, through Pegan Pond.