Page:Popular Science Monthly Volume 38.djvu/406

392 health was restored. Growers of hyacinths have noticed a marked effect on their blooming when they are put in glasses of certain colors.

This age is a peculiarly health-seeking one, and it does not seek health, as the Greeks did, by early rising, temperance, open-air exercise, and training; but it asks how health can be preserved and promoted by the removal of external sources of disease, so that it may have freedom to infringe with comparative impunity Nature's laws. External poisons are the most important things to protect ourselves from, especially when we have enfeebled our bodies, and these are mostly conveyed to us by mephitic vapors and what the doctors call septic dust. We want our houses and other buildings so constructed that they can be freed outside from their palls of dust and soot by means of a fire-engine or a sponge, and inside by the broom, the dusters, and the flannels of the housemaid.

Foul and poisonous air has scarcely any connection with decoration, but, with one or two exceptions, is in relation with pure science and its applications. The exceptions are when some of the materials used for decoration have a pernicious chemical action on the air, or parts of their substance readily come off and poison us when we breathe, or when in contact with our skin. The former is said to be the case when preparations of arsenic and some other dyes and pigments are used and are not varnished. The dust that is not septic consists of minute particles of raw or cooked earth, stone, and metal, and the ill effect it may produce can only be from irritation of the mucous surfaces, by clogging fine vessels, or by getting into parts where it is not wanted. Particles of some metals, if numerous enough, may poison us, as fire-gilders are poisoned by mercurial fumes. The septic dust consists of particles of vegetable or animal fiber, sometimes laden with the germs of disease, the pollen of flowers, by some of which hay fever is said to be produced, the eggs of microscopic creatures, and microscopic creatures themselves. Another source of poisoning is by animal and human exhalations.

Anything that forms a dust-trap is as far as possible to be avoided, particularly when these traps can only be partially emptied at long intervals, for every breath of air dislodges some of the lighter particles. The absorbents of the foul-smelling exhalations have also the property of imparting them to damp air, by which we are poisoned or repoisoned. Consequently we want to avoid as much as possible all woven and felted stuffs in our houses, and to have all wood and paper protected by varnish.

Few of us can expect to live in houses built of polished granite, porphyry, and jasper, and adorned with precious stones, but we may expect to live in those protected and embellished with