second, 39 in the third, 44 in the fourth, 24 in the fifth, 12 in the sixth, 4 in the seventh, and I in the eighth. The predisposition to the disease is frequently retained throughout life. The affection is more common in those with pulmonary emphysema.

Exciting Causes.-Climatic influences are very curious, some patients having asthma in some places and not in others, without apparent reason. Vegetable and terrestrial dust and irritating vapors may induce an attack. In this respect asthma closely resembles hay fever, with which disease it is closely allied, and which it frequently complicates. Ipecac, sulphur, iodine, the pollen of many flowers and grasses, the irritant odor of violets, roses, and strawberries, the dust of feathers, and the emanations of certain animals afford familiar examples of personal susceptibility. Sudden mental shocks and deep emotions may induce asthma. The most frequent cause of an attack in those predisposed to asthma is bronchitis, and if in such patients bronchitis can be avoided, attacks of asthma are rare.

Reflex causes are common. Nasal polypi, hypertrophic rhinitis, naso-pharyngeal adenoids, and enlarged tonsils are frequently found, and the cure of these conditions will in many cases remove the liability to asthma. It is too much to claim that nasal and pharyngeal lesions comprise the only cause, however, as has been done by some. Among other reflex causes are uterine and ovarian diseases, overloading of the stomach, and the taking of certain articles. of food.

Pathology. As asthma is a functional disease, there is no regular lesion, although in old asthmatics emphysema and chronic bronchitis are often present.

Symptoms. There may be premonitions-a sense of drowsiness, depression of the mind, tightness in the chest, or peculiar feelings in individual cases that mean an impend

ing attack. The paroxysm usually begins at night with a sense of dyspnoea and with laborious efforts at breathing. The patient cannot lie down, but sits or stands, usually by an open window. Inspiration is spasmodic; expiration is prolonged and wheezing. The accessory muscles of respiration are called into play; the face is livid and distressed, and perhaps cyanotic. Limpid urine is usually passed in large quantities. There is a cough, tight at first, with balllike gelatinous masses of sputum-the "perles" of Laennec. These balls can be unrolled in water; they represent mucous casts of the smaller bronchi. They frequently have a distinct spiral form, and they are known as "Curschmann's spirals" (Fig. 24), in which there is frequently a central

FIG. 24.-Curschmann's spirals: a, central fibre (after Curschmann).

translucent filament composed of altered mucin. In addition are found in the sputum the pointed octahedral crystals described by Leyden, identical with those found in semen and in leukæmic blood (Fig. 25).

Physical Signs.-The chest is fixed and enlarged-often from 6 to 8 centimeters larger in circumference than normal. Expansion is poor, especially laterally, and is in strong contrast to the muscular attempts of respiration. Inspiration is short; expiration is prolonged and wheezing.

The diaphragm is low and moves but slightly. Percussion shows an increased area of pulmonary resonance. The note may be normal or hyper-resonant or tympanitic. On auscultation are heard all varieties of sibilant, sonorous, cooing, and whistling râles, especially during expiration.

FIG. 25.-Charcot-Leyden's asthma-crystals (after Riegel).

The expiratory murmur may be prolonged, or breathing sounds may be absent or be obscured by the râles.

The duration of the attack varies from several hours to a number of days. In the more protracted cases the symptoms are worse at night. Between the attacks there may be dyspnoea, wheezing respiration, and cough. In the longstanding cases emphysema and chronic bronchitis develop, resulting in chronic invalidism.

The prognosis for life is good, death never resulting during a paroxysm.

Treatment. During the attack immediate treatment is required to relax the contracted bronchioles. A number of

remedies may be employed, Of these remedies amyl nitrite is the most serviceable, a perle containing from 2 to 5 minims being broken in a handkerchief and the vapor inhaled. Hot stimulants or spirits of chloroform in hot water may be given, while whiffs of chloroform may be required in aggravated cases. Permanent relief is often afforded, even in obstinate cases, by a hypodermic injection of morphine. Nitroglycerin, gr. every two or three hours, is of service in the more protracted cases. Choral in 10- or 15-grain doses often affords relief. Antipyrine, gr. xv, or phenacetine, gr. x, may be used, repeated every three hours. Good results are claimed for the fluid extract of grindelia robusta in 3j doses every four hours. The smoke of cigarettes containing hyoscyamus, belladonna, or stramonium may be inhaled, or pastilles may be made from these drugs, with the addition of potassium chlorate or nitrate. Inhalations of cigar-smoke are frequently of great value. Paper saturated with a strong solution of potassium nitrate burnt in the room before retiring will often ward off a nocturnal attack.

Between attacks antispasmodics should be given. Iodide of potassium in gr. v-xv doses three times a day, with or without the addition of 5 grains of chloral to each dose, is of great benefit. Nitroglycerin, gr. every four to six hours, may be used. The systematic inhalation of compressed air has been recommended strongly.

The diet should be such as not to induce flatulence, carbohydrates being used in great moderation. The patient should not retire to bed on a full stomach, and it is usually best for the heavy meal of the day to be taken at noon.

If nasal polypi or hypertrophies are present, they should be removed.

For every asthmatic there are localities in which he has little or no asthma. The particular locality of exemption

should be found by each patient to suit his individual case, as no regular rule can be laid down to suit all patients.

3. DISEASES OF THE LUNGS.

(a) CIRCULATORY DISTURBANCES.

CONGESTION OF THE LUNGS.

Congestion may be either active or passive.

Active congestion occurs with acute inflammation of the lungs, with over-action of the heart, and from the inhalation of hot or irritating vapors. It may cause increase of dyspnoa, cough, and expectoration, with a moderate degree of fever, but about its symptomatology not much is accurately known.

Most authors describe a rapidly fatal form of congestion occurring after exposure to cold or after over-exertion. Passive Congestion.-Two distinct forms of passive congestion are recognized-mechanical and hypostatic.

1. Mechanical congestion is known as "brown induration" or the "pneumonia of heart disease"; it is described under the heading of Chronic Venous Congestions of Heart Disease, page 209.

2. Hypostatic congestion of the posterior portions of the lungs is often found as the result of post-mortem changes. It is common in those confined to bed for a long time in a weakly condition, as the combined result of feeble circulation and the effect of gravity. In coma and in cerebral injuries, such as cerebral hemorrhage, it is often seen in its most pronounced degree. The affected portions of lung are congested, oedematous, heavy, and imperfectly aërated.

The congestion may be complicated by patches of consolidation resembling either broncho-pneumonia or a lobar