Under this name a medical writer in Scotland, Dr. Francis Home, in 1765, described an affection in children of the windpipe or the upper portion of the air tubes (larynx and trachea), involving liability to death from suffocation, and characterized by a peculiar ringing, metallic cough. He applied also to the affection the classical name suffoca-tio stridula; and the term cynanche trachealis has been used by writers in the same sense. The name croup has been in popular use ever since the date of Home's writings, and employed also by physicians, to denote diseases in the windpipe giving rise to more or less suffocation, together with the peculiar cough just referred to. " The hives " is a popular term formerly much in vogue in this country, having the same meaning. Writers, however, who came after Home, pointed out the fact that suffocative symptoms, accompanied by the croupal cough, occur in connection with different forms of disease in the same situation. The late Prof. John Ware of Boston was the first to indicate clearly the different affections embraced under the name croup. They are as follows: 1. A spasmodic affection of certain muscles of the windpipe (larynx), occurring independently of inflammation. This affection has been distinguished as spasmodic croup.

Its distinctive features are a sudden attack, generally at night, suffocation apparently being imminent, and the peculiar cough very strikingly marked. This affection, though from the violence of the symptoms apt to occasion great alarm, is devoid of danger. . After a period varying from a few minutes to several hours, complete relief is obtained, no symptoms of disease within the windpipe remaining. A frequent cause of the attack is indigestion.. 2. An affection which, in like manner, involves spasm, the symptoms of suffocation together with the cough being wholly due to the spasmodic condition; but, in addition, there is a slight or subacute inflammation of the membrane lining the larynx and trachea. The inflammation does not invest the attack with any danger. Relief is obtained, but a little cough remains, with perhaps some hoarseness. Prof. Ware distinguished this affection as catarrhal croup. 3. An acute inflammation of the membrane lining the windpipe, the proper nosological name for which is acute laryngitis. The inflammation is essentially the same as in the ordinary acute inflammatory affections of the mucous membrane in other situations, and, by way of distinction from the unusual variety to be presently noticed, it may be called simple acute laryngitis.

The swelling of the membrane gives rise to more or less obstruction to the passage of the air in breathing; but spasm is also an element in this form of disease, causing paroxysms of increased difficulty in breathing, accompanied by croupal cough. Simple acute laryngitis in children proves fatal in only a small proportion of cases. It is less serious in the child than in the adult, owing to the fact that in the latter it is apt to give rise to serous effusion beneath the mucous membrane, the obstruction, and consequent danger of suffocation, being thereby increased. Prof. Ware distinguished this form as inflammatory croup. 4. The form to which par excellence the name croup is applied, which it is customary to call "true croup," and the three other affections different varieties of " false croup." In true croup the mucous membrane lining the larynx and trachea is inflamed. The disease is therefore laryngitis; but the inflammation has a striking peculiarity which distinguishes it from a simple acute laryngitis, viz.: an exudation, that is, an effusion of fibrine which coagulates upon the mucous surface and forms a layer like a membrane, called a false membrane.

The presence of this false membrane is a cause of obstruction in addition to the swelling of the mucous membrane; hence the greater persistent difficulty in breathing and danger from suffocation in true croup, as compared with the three varieties of false croup. The disease proves fatal in a very large proportion of cases, and the suffering from the want of breath is very great. In distinction from simple acute laryngitis, the affection is called by a variety of names, such as membranous or pseudo-membranous, fibrinous, plastic, exudative, and diphtheritic laryngitis or croup. The production of an analogous false membrane is the distinctive characteristic of the disease now known as diphtheria. (See Diphtheria.) Diphtheritic laryngitis is developed gradually. The first local symptom is hoarseness, which may exist for one, two, or three days before distress from obstruction ensues. The latter at length becomes marked, and progressively increases, the labor of breathing and the suffering from a sense of the want of air increasing in proportion. The voice become extinct. The cough is croupal, but in a degree less than in the so-called spasmodic croup. Spasm, however, is an element in true croup, as it is in the several varieties of false croup, but not to the same extent.

Death takes place from slow suffocation, or apnoea, in from four to six days. In the cases which end in recovery, the false membrane is thrown off and expectorated. Portions of the membrane are sometimes expectorated in fatal cases, but a renewal of exudation takes place. The exudation sometimes extends to the bronchial tubes, and this lessens the few chances of recovery. Pneumonia not infrequently occurs as a complication. The suffering from the sense of suffocation generally becomes less toward the close of life, owing to the perceptions having become blunted, and the spasmodic element being less marked. Sometimes, owing to these causes, there is an appearance of improvement which is apt to lead to a delusive hope that the patient is essentially better. - In treating cases of true croup, the great object is to expedite the separation of the false membrane. The inhalation of warm vapor or steam is the most effective measure for this object. The presence of lime is supposed to be useful by giving to the vapor a solvent property. Slacking lime in the room is a convenient method of producing a warm vapor, and securing whatever benefit is to be derived from the presence of lime in the vapor inhaled.

In addition, the room should be kept filled with vapor from boiling water, and the temperature should be between 80° and 90°. Emetics may be useful when the false membrane has been thrown off, by effecting its expulsion from the larynx. The application of cold to the neck is recommended, with a view to lessen the intensity of the inflammation and prevent spasm. A highly important part of the treatment consists in giving nutritious food, together with tonic remedies and perhaps alcoholic stimulants, in order to prolong life until the separation and removal of the false membrane have been effected. The measures of treatment which were formerly in vogue, bleeding, mer-curialization, counter-irritation, and the frequent repetition of powerful emetics, are now generally regarded by physicians as injudicious. Opening the trachea (tracheotomy) is to be employed when it is apparent that the disease will otherwise in all probability prove fatal. The chances of saving life by means of this operation are not many; but it cannot be doubted that tracheotomy sometimes rescues patients from impending death. If not successful, it affords relief from the distress of suffocation, and substitutes an easier mode of dying; it is therefore justifiable on the ground of euthanasia.

True croup, as a rule, affects children between two and seven years of age. Exceptionally it occurs at other periods of childhood and after adult age. The varieties of false croup in which spasm is exclusively the cause of the temporary obstruction of breathing call for measures of treatment which relieve the spasmodic condition, namely, warm applications to the throat, the inhalation of warm vapor, and anodynes. When dependent on indigestion, a mild emetic is promptly efficacious. Simple acute laryngitis in the child claims mild measures designed to diminish the intensity and duration of the inflammation, together with remedies to palliate spasm. - None of the varieties of false croup have any tendency to eventuate in the membranous variety or true croup. Considering this fact, and the great danger in cases of true croup, it is extremely important to discriminate between these different affections, which have unfortunately been grouped together. Anxiety on this score may often be relieved by bearing in mind that if the voice or the cry be unaffected, that is, if there be no hoarseness, the affection is purely spasmodic, and without danger.

It is also important to be borne in mind that the dangerous affection, true croup, is generally developed gradually; and in a child, especially between two and seven years of age, hoarseness should always excite apprehension, and still more if with the act of inspiration the nostrils dilate, although there may be no evidence of distress from obstructed breathing. - An affection analogous to spasmodic croup, consisting in spasm of those muscles of the larynx which close the glottis, occurring chiefly in infants, is known as spasm of the glottis or laryngismus stridulus. It has been called thymic asthma, from a fancied dependence on enlargement of the thymus gland. It occurs in paroxysms, during which respiration is greatly obstructed. Sometimes, although very rarely, it causes death by suffocation. It exists in a mild form when infants are said to have " spells of holding the breath." The holding of the breath, however, is due not to mental per-verseness, but to an involuntary contraction of the muscles of the glottis. A tendency to spasm of these muscles exists in some children as an idiosyncrasy. Severe paroxysms are apt to arise from the irritation of teething.

The milder paroxysms are quickly made to cease by a sudden impression on the nervous system, as by slapping the back, or sprinkling a little cold water on the face. If the paroxysms are severe, it is important to ascertain and remove the exciting causes (for example, dividing the gums), and to employ measures to improve the general health and vigor. Spasm of the glottis, although one of the affections belonging espe-pecially to infancy, may occur at any period of life. It is among the varied nervous manifestations embraced under the name hysteria, and it may be caused by a tumor so situated as to irritate the nerve which furnishes fibres to the muscles of the glottis, namely, the recurrent laryngeal nerve.