und, which gives rise to
the name of the disease. Several such fits of coughing may follow one
another and are often succeeded by vomiting and the expulsion of a
large amount of phlegm or mucus, which is sometimes streaked with
blood. In mild cases there may be six to twelve attacks in twenty-four
hours; in severe cases from forty to eighty. The attacks last from a
few seconds to one or two minutes. Occasionally the whoop comes before
the coughing fit, and sometimes there may be no whooping at all, only
fits of coughing with vomiting. Between the attacks, puffiness of the
face and eyes and blueness of the tongue persist. The coughing fits
and whooping last usually from three to six weeks, but the duration of
the disease is very variable. Occasionally it lasts many months,
especially when it occurs in winter. The contagiousness of whooping
cough continues about two months, or ceases before that time with the
cessation of the cough. Oftentimes there may be occasional whooping
for months; or, after ceasing altogether for some days, it may begin
again. In neither of these conditions is the disease considered still
contagious after two months. When an attack of whooping is coming on,
the child often seems to have some warning, as he seems terrified and
suddenly sits up in bed, or, if playing, grasps hold of something, or
runs to his mother or nurse. Coughing fits are favored by emotion or
excitement, by crying, singing, eating, drinking, sudden change of
temperature, and by bad air.

=Complications and Sequels.=--These are many and make whooping cough a
critical disease for very young children. Bronchitis and pneumonia
often complicate whooping cough in winter, and diarrhea frequently
occurs with it in summer. Convulsions not infrequently follow the
coughing fits in infants, and, owing to the amount of blood forced to
the head during the attacks, nosebleed and dark spots on the forehead
and surface of the eyes appear from breaking of small blood vessels in
these places. Severe vomiting and diarrhea occasionally aggravate the
case, and pleurisy and consumption may occur. The violent coughing may
permanently damage the heart. Rupture of the lung tissue happens from
the same cause, and paralysis sometimes follows breaking of a blood
vessel in the brain. But in the vast majority of cases in children
over two years old no dangerous sequel need be feared.

=Outlook.=--Owing to the numerous complications, whooping cough must
be l