particles which should pass through them stay in the body, and cause
disease in the lungs or other parts."

Why should you sit and stand erect?--"Because, if I am in the habit of
stooping, my lungs will be crowded, and will not have enough room to move
freely."

Why should you keep all parts of the body warm?--"Because chilling any part
of the body causes the blood to chill in that part, and thus hinders its
circulation."

Why should you not change your winter clothing too early in the spring of
the year?--"I may take cold if not warmly clothed during the cool days of
early spring."

Why should you avoid draughts of cool air?--"Because the cool air blows
upon some parts of the body and closes the pores of the skin, checking the
perspiration, and hindering the circulation of the blood."

Why should you not rush suddenly from a warm to a cool place?--"Because
when warm the pores of the skin are open; if I rush suddenly into the cool
air, these pores are closed too quickly."

Why does stopping the perspiration hurt the lungs more or less?--"The
impurities it ought to carry away remain in the body, make the blood
impure, and produce disease in some part; very often that part is the
lungs."

What harm does alcohol do in the lungs?--"It fills the lungs with impure
blood."