ASTHMA ASTLEY roids probably falls far short of one fourth of the earth's mass. More than a third of the known asteroids have been discovered iu the two months April and September, and less than a third in the six months January, February, June, July, November^and December. ASTHMA (Gr. dofya, from aeiv, to blow), a disease characterized by an extreme difficulty of respiration, which is worse at certain sea- sons of the year and particular periods of the day, being generally most severe at night. The difficulty of breathing is increased by vio- lent emotions, damp atmosphere, excess of any kind, strong exercise, running, walking quickly, or ascending a flight of stairs. It is also more laborious in a horizontal position, and hence more distress is felt in bed at night ; the warmth of the bed also excites increased secretion of the mucous follicles, and this blocks up the air passages more completely, causing paroxysms to be more frequent than during the day. The patient seeks relief by sitting upright in bed, or bending his body forward, and endeavoring to expand the chest mechanically by every pos- sible means. Old persons are more liable to the disease than young. Some writers describe the disease mainly as a nervous affection ; others as the result of organic lesion of the heart and blood vessels ; while others again attribute it to dila- tation of the air vesicles of the lungs. All these and many other complications may exist. It is now believed that spasmodic asthma is caused by a spasm of the muscular fibres en- circling the bronchial tubes, especially the smaller branches. The existence of these fibres is placed beyond a doubt by microscopic examination. In common asthma the lining membrane of the air passages is more or less affected as in chronic bronchitis, but the af- fection of the mucous membrane extends further down into the lungs, the air cells are more obstructed, and the conformation of the chest itself is often somewhat contracted and defective. The action of the diaphragm is imperfect, a3 well as that of the walls of the chest ; and hence it is that, from want of in- nervation and free action in these parts, the disease is commonly deemed nervous, as distin- guished from chronic bronchitis, which affects the bronchial mucous membrane chiefly. In spasmodic asthma, the nerves are still more deeply implicated; their action seems de- fective in the respiratory organs, as stammer- ing shows imperfect nervous action in the or- gans of speech ; and in both cases the diffi- culty is increased by physical or moral excite- ment. Chronic asthma seldom shortens life, where patients carefully avoid all violent emo- tions, exercise, and excess, although spasmodic paroxysms may endanger life at any time where these precautions are neglected. Attacks of spasmodic asthma generally occur during the first sleep, soon after midnight, or very early in the morning. The patient suddenly awakea with a sense of suffocation, tightness of the chest, and difficulty of breathing. The respi- ration is wheezing and laborious, the shoulders are raised, and every effort made to enlarge the chest. The pulse is usually quick, weak, and irregular ; the lower extremities cold. When cough and expectoration come on, the patient is relieved. The spasm, however, may con- tinue half an hour or more, and even as much as three or four hours. Asthma is often com- plicated with diseases of the heart or with chronic bronchitis, acting as a source of per- manent congestion, predisposing the parts to be more easily thrown into a state of spasm. Sometimes severe attacks of dry catarrh are aggravated by spasm, as in the "bronchial asthma" of Andral. The most common con- sequences or concomitants of the disease are chronic inflammation and dilatation of the bronchi ; emphysema and oedema of the lungs ; haemoptysis ; tubercular deposits ; hypertrophy and dilatation of the cavities of the heart; effusions into the pericardium, the pleura, and sometimes congestion and effusions in the head, giving rise to coma or apoplexy. The treatment of the paroxysm consists in admin- istering narcotics and antispasmodics, to be given if possible as soon as the first sensations are felt. Strong coffee, laudanum, and ether are among the best ; and stramonium smoked as tobacco is often very useful, but should be used with caution where the heart is diseased. Those medicines are most effectual which pro- duce expectoration. ASTI (anc. Aita Pompeia), a city of N. Italy, in the province of Alessandria, 36 m. by rail E. S. E. of Turin; pop. in 1872, 31,033. In the middle ages it was the capital of the republic of Asti, which maintained its independence from 1098 to 1155, in which latter year the city was burned by Frederick Barbarossa. Old walls surround it, and it contains several cele- brated buildings. Near the city is made the wine which bears its name. Asti is the birth- place of Alfieri. AS'I'IK, Jean Frederic, a French writer, born in 1822. He was for some time pastor in New York city, and subsequently professor of phi- losophy at Lausanne. Among his works are : Le reveil religieux des fitati-Unis, 1857-'8 (Lausanne, 1859), and ffutoire de la republique des &tats- Unii depute V etablissement dei pre- mi&res colonies jusgu'A Selection du president Lincoln, 1620-1860 (2 vols., 1865). ASTLET, Philip, an English equestrian, born at Newcastle-under-Lyne in 1742, died in Paris, Oct. 20, 1814. He served seven years in the light horse, and receiving an honorable dis- charge supported himself for some time by ex- hibitions of horsemanship. He at length ac- quired sufficient means to build a circus or amphitheatre, which he conducted successfully for many years, though it was several times partially burned and rebuilt. In 1804 he leased it to his son. He also built for his own use 19 theatres in London, Paris, find Dublin, and in connection with Antoine Franconi assisted to establish the "Olympic Circus." He pub-
