Asterol´epis, a genus of primitive ganoid fishes, found only in a fossil state in the Old Red Sandstone. They were about 1 foot long, and the head and body were enclosed in armour of strong bony plates.
Asthma (ast´ma), difficulty of respiration, returning at intervals, with a sense of stricture across the chest and in the lungs, a wheezing, hard cough at first, but more free towards the close of each paroxysm, with a discharge of mucus, followed by a remission. Asthma is essentially a spasm of the muscular tissue which is contained in the smaller bronchial tubes. It generally attacks persons advanced in years, and seems, in some instances, to be hereditary. The exciting causes are various—accumulation of blood or viscid mucus in the lungs, noxious vapours, a cold and foggy atmosphere, or a close, hot air, flatulence, accumulated fæces, violent passions, organic diseases in the thoracic viscera, &c. In recent years a treatment first used by Dr. Alexander Francis has come into prominence. By far the most important part of the treatment consists in obviating or removing the several exciting causes. It seldom proves fatal except as inducing dropsy, consumption, &c.
Asti (a˙s´tē), a town of Northern Italy, province of Alessandria, 28 miles E.S.E. of Turin, the see of
a bishop, with an old cathedral. In the Middle Ages it was one of the most powerful republics of Northern Italy. It was the birthplace of Alfieri, the poet, whose statue adorns the principal square. There is also an equestrian statue of King Humbert. The industries comprise silk, matches, gold, mosaic wares, &c. A favourite wine is produced in the neighbourhood. Asti, anciently Asta, was a place of some importance under the Roman emperors, and in the Middle Ages was an independent republic. Pop. 41,252.
Astig´matism (Gr. a, not, stigma, spot, mark), a malformation or imperfection, congenital or accidental, of the globe of the eye, in consequence of which the individual does not see objects clear and distinct, but with a blurred outline. It is due to the cornea or transparent outer coat of the eye not being regularly spherical, but having different degrees of curvature in different directions. Usually the degree of convexity is not the same horizontally as it is vertically, so that the rays from an object, instead of converging into one focus, meet in more than one. If a person with this defect is looking at vertical lines crossed by horizontal ones he will see the one set more distinctly than the other, though a slight movement will enable him to see the other distinctly also, but not at the same time. Almost all eyes are more or less astigmatic, but persons only become aware of it when it is excessive. Special lenses are required to correct it—usually lenses plane in one direction and concave or convex in the other. Short sight or long sight is often associated with astigmatism, so that suitable spectacles cannot be very easily provided.
Astle, Thomas, English antiquary, born 1735, died 1803. He was a trustee of the British Museum and keeper of the public records in the Tower. His chief work, The Origin and Progress of Writing, appeared in 1784, and the portion dealing with mediæval handwriting is still of value. He formed a famous collection of MSS., the most valuable portion of which is now in the British Museum.
Astom´ata, one of the two groups into which the Protozoa are divided with regard to the presence or absence of a mouth, of which organ the Astomata are destitute. The group comprises two classes, Gregarinida and Rhizopoda. See Stomatoda.
Aston Manor, formerly a municipal and parliamentary borough of Warwickshire, England, situated about 1½ miles E.N.E. of Birmingham, and engaged in similar branches of industry. It was incorporated with Birmingham in 1911 and gives its name to one of its parliamentary divisions. Pop. 75,029.
Astor, John Jacob, born near Heidelberg, Germany, 1703, died at New York, 1848. In 1783 he emigrated to the United States, settled at New York, and became extensively engaged in the fur trade. In 1811 the settlement of Astoria, founded by him, near the mouth of the Columbia River, was formed to serve as a central depot for the fur trade between the lakes and the Pacific. He subsequently engaged in various speculations, and died worth £4,000,000, leaving £80,000 to found the Astor Library in New York. This institution is contained in a splendid building, enlarged in 1859 at the cost of his son, and comprises about 260,000 volumes. Since 1895 it has formed part of the New York public library.—His great-grandson, William Waldorf Astor, born in 1848, died in 1919, naturalized in England in 1899, was made a baron in 1916 and a viscount in 1917.
Astor, Lady. Nancy Witcher, Viscountess Astor, married the second Viscount Astor in 1906. She is a daughter of the late Colonel Chiswell Dabney Langhorne, of Virginia, United States. In Nov., 1919, she was elected member of Parliament for the Sutton division of Plymouth, and was the first woman to take a seat in the House of Commons.