(_h_) Whooping cough is the name of an affection deriving its significance from a characteristic which is peculiar to this cough. It commences like an ordinary bronchitis such as is the result of taking cold; there is the usual hoarseness, tickling in the throat, dry cough, sneezing, running from the nose; the eyes are red and watery, and there is more or less fever. Sometimes the cough is ordinary, but at other times it has a sharp metallic clang from the beginning. Owing to certain marked periods in the course of the affection it has been found convenient to divide it into three stages which may usually be distinguished, although in a certain proportion of cases the first stage (comprising some of the symptoms that have been enumerated above) may be submerged into the second or whooping stage. The first stage may last from four to five days to as many weeks. The second stage is when the peculiar sound or whoop begins; it consists of a great number of violent paroxysms, rapidly-recurring spasmodic coughs, until most of the air in the lungs is expired; there is then a sense of suffocation and the child becomes bluish red over the entire head and face, from which the German designation _blue cough_ has originated. During this spell the face swells and the eyeballs become congested and bulge from their orbits and the nose often begins to bleed, while the urine and feces are often involuntarily ejected and the contents of the stomach thrown up from the violent contraction of the diaphragm. In a few moments the spell is broken by a protracted, whistling croupy inspiration, and this constitutes the whoop. The whooping generally grows worse the first two or three weeks, after which time in favorable cases the cough gradually becomes milder, but this is not the rule by any means. I have had it in my own family to last, in two instances, six months, and in another eight months before the children had fully recovered. Laughing or crying, swallowing dry, irritating morsels of food or cold and impure air will bring on a paroxysm of cough. When several children are affected together, the coughing of one will make the others cough. The third stage is when the cough is wearing off and has lost its severity. The expectoration consists now of a yellowish or green-colored mucus; in otherwise healthy children this lasts only a few weeks, but in weakly or scrofulous ones it may last for several months. This disease is not as yet thoroughly understood. It is an epidemic, contagious bronchial catarrh, involving the nerves of respiration and attacks an individual but once. When complications arise the affection becomes exceedingly dangerous and the most common of these is pneumonia.