e a window-blind, so that air is freely
transmitted without exposing the interior.

When we speak of fresh air, we insist on the full rigor of the term. It
must not be the air of a cellar, heavily laden with the poisonous
nitrogen of turnips and cabbages, but good, fresh, out-door air from a
cold-air pipe so placed as not to get the lower stratum near the ground,
where heavy damps and exhalations collect, but high up in just the
clearest and most elastic region.

The conclusion of the whole matter is, that, as all of man's and woman's
peace and comfort, all their love, all their amiability, all their
religion, have got to come to them, while they live in this world,
through the medium of the brain,--and as black, uncleansed blood acts on
the brain as a poison, and as no other than black, uncleansed blood can
be got by the lungs out of impure air,--the first object of the man who
builds a house is to secure a pure and healthy atmosphere therein.

Therefore, in allotting expenses, set this down as a _must-be_: "Our
house must have fresh air,--everywhere, at all times, winter and
summer." Whether we have stone facings or no,--whether our parlor has
cornices or marble mantels or no,--whether our doors are machine-made or
hand-made. All our fixtures shall be of the plainest and simplest, but
we will have fresh air. We will open our door with a latch and string,
if we cannot afford lock and knob and fresh air too,--but in our house
we will live cleanly and Christianly. We will no more breathe the foul
air rejected from a neighbor's lungs than we will use a neighbor's
tooth-brush and hair-brush. Such is the first essential of "our
house,"--the first great element of human health and happiness,--AIR.

"I say, Marianne," said Bob, "have we got fireplaces in our chambers?"

"Mamma took care of that," said Marianne.

"You may be quite sure," said I, "if your mother has had a hand in
planning your house, that the ventilation is cared for."

It must be confessed that Bob's principal idea in a house had been a
Gothic library, and his mind had labored more on the possibility of
adapting some favorite bits from the baronial antiquities to modern
needs than on anything so terrestrial as air. Therefore he awoke as from
a dream, and taking two or three monstrous inhalations, he seized the
plans and began looking over them with new energy. Meanwhile I went on
with my prelection.

* * * * *

The seco