The houses of the grandmothers and great grandmothers of this generation, at least the country houses, with front door and back door always standing open, winter and summer, and a thorough draught always blowing through--with all the scrubbing, and cleaning, and polishing, and scouring which used to go on, the grandmothers, and still more the great grandmothers, always out of doors and never with a bonnet on except to go to church, these things entirely account for the fact so often seen of a great grandmother, who was a tower of physical vigour descending into a grandmother perhaps a little less vigorous but still sound as a bell and healthy to the core, into a mother languid and confined to her carriage and house, and lastly into a daughter sickly and confined to her bed. For, remember, even with a general decrease of mortality you may often find a race thus degenerating and still oftener a family. You may see poor little feeble washed-out rags, children of a noble stock, suffering morally and physically, throughout their useless, degenerate lives, and yet people who are going to marry and to bring more such into the world, will consult nothing but their own convenience as to where they are to live, or how they are to live. [Sidenote: Don't make your sickroom into a ventilating shaft for the whole house.] With regard to the health of houses where there is a sick person, it often happens that the sick room is made a ventilating shaft for the rest of the house. For while the house is kept as close, unaired, and dirty as usual, the window of the sick room is kept a little open always, and the door occasionally. Now, there are certain sacrifices which a house with one sick person in it does make to that sick person: it ties up its knocker; it lays straw before it in the street. Why can't it keep itself thoroughly clean and unusually well aired, in deference to the sick person? [Sidenote: Infection.]