WHOOPING-COUGH. 99 



to play, or to eat with good appetite, until a new fit interrupts their 

 comfort. 



It is upon these alternations of symptoms that the theory is based 

 that whooping-cough is a neurosis of the par-vagum nerve. Although 

 laughing, crying, loud speaking, insignificant acts of deglutition, often 

 give rise to the seizures, yet we cannot deny that they are not always 

 the result of demonstrable external provocation. Indeed, we must ad- 

 mit that the paroxysms often increase in frequency during the night, 

 although the room has not grown colder. It is difficult to assign a 

 reason for this circumstance. If, however, we question an observing 

 mother, or watch a sleeping child ourselves, until the whooping-cough 

 awakens it, we may satisfy ourselves that the fit is preceded by a slight 

 and very brief, although perceptible, laryngeal rattle, and if we look into 

 the child's throat, as soon as he begins to cough, the pharynx will be 

 /bund filled with that tough mucus the accumulation of which pro 

 eokes the attack, and the ejection of which ends it. The secretion 

 once discharged, some time elapses before a fresh collection of it pro* 

 duces a new coughing-fit, and thus the semblance of intermission is given 

 to the apparently rhythmical march of the disease. Every coughing- 

 spell is a new source of irritation to the mucous membrane of the larynx. 

 The more violent it has been, so much the more rapidly does new secre- 

 tion form, and so much the sooner is the next paroxysm to be expected. 



The convulsive stage having lasted three or four weeks, or in other 

 cases as many months, the stadium criticum sen decrement^ or stage 

 of decline, gradually sets in. The catarrhal secretion loses its tenacious, 

 transparent quality, becomes more liquid, yellow, and opaque. The 

 sputa cruda become sputa cocta. Here, too, the altered secretion affords 

 evidence that the hypersemia and irritability of the mucous membranes 

 are subsiding. The paroxysms are no longer provoked by slight exter- 

 nal irritants ; and the secretion becoming more easy of ejection, and the 

 reflex symptoms growing milder, as irritability of the mucous membranes 

 decreases, the fits themselves* are shortened. The vomiting, which for- 

 merly closed the seizure, ceases to occur, excepting when, the larynx 

 chancing to encounter some irritant of unwonted activity, a coughing- 

 spell of the ancient violence is provoked. Relapses are extraordinarily 

 apt to occur, if the child be not carefully protected from all pernicious 

 influences. The mucous membrane remains extremely sensitive for 

 months, although the disease be extinct and the child be recovered. 

 Every slight catarrh is attended by spasmodic stricture of the glottis, 

 upon coughing, and recalls to mind the old affection from which it has 

 long been free. 



Physical examination made during the interval affords no character- 

 istic evidence. Percussion is normal, and auscultation reveals signs of 



