Note 10 — II.—HEALTH OF HOUSES.[7]

Diseases are not individuals arranged in classes, like cats and dogs, but conditions growing out of one another.

Is it not living in a continual mistake to look upon diseases, as we do now, as separate entities, which must exist, like cats and dogs? instead of looking upon them as conditions, like a dirty and a clean condition, and just as much under our own control; or rather as the reactions of kindly nature, against the conditions in which we have placed ourselves.

I was brought up, both by scientific men and ignorant women, distinctly to believe that small-pox, for instance, was a thing of which there was once a first specimen in the world, which went on propagating itself, in a perpetual chain of descent, just as much as that there was a first dog, (or a first pair of dogs), and that small-pox would not begin itself any more than a new dog would begin without there having been a parent dog.

Since then I have seen with my eyes and smelt with my nose small-pox growing up in first specimens, either in close rooms or in overcrowded wards, where it could not by any possibility have been "caught," but must have begun.

Nay, more, I have seen diseases begin, grow up, and pass into one another. Now, dogs do not pass into cats.

I have seen, for instance, with a little overcrowding, continued fever grow up; and with a little more, typhoid fever; and with a little more, typhus, and all in the same ward or hut.

Would it not be far better, truer, and more practical, if we looked upon disease in this light?

For diseases, as all experience shows, are adjectives, not noun substantives.