If the nasal passages are put in a healthy condition, strict obedience

to the rules of individual hygiene will almost wholly prevent colds
If the nasal passages are put in a healthy condition, strict obedience
to the rules of individual hygiene will almost wholly prevent colds. In
fact, except where actual nasal defects exist, the frequency of colds is
usually a fair indication of how hygienically a person is living. The
following points need especial emphasis, though they repeat in some
cases what has already been said in the text.