ASTEROIDS 



435 



ASTHMA 



inches. Asters flower late in summer and in 

 some places blossom until November or De- 

 cember. They adapt themselves readily to 

 cultivation and are popular garden plants. 



ASTERS 



Every aster In my hand 



Goes home loaded with a thought. 



From EMERSON'S The Apology. 



Many poets have told of the late-flowering 

 habits of the aster, none more beautifully than 

 Bryant, in his Death of the Flowers: 



The wlndflower and the violet, they perished long 



ago, 

 And the brier-rose and the orchis died amid the 



summer glow ; 

 But on the hills the golden rod, and the aster in 



the wood. 

 And the yellow, sunflower by the brook. In 



autumn beauty stood. 



ASTEROIDS, as'teroyds, or PLANETOIDS, 

 the name of a group of many minor planets, 

 revolving between the orbits of Mars and 

 Jupiter, and occupying a place in the solar 

 system which would naturally belong to a 

 planet. The diameter of the largest does not 

 exceed 488 mil<s, \\lnir most of the others are 

 v.-ry much smaller', some being less than 

 ity miles in diameter. The known ones 

 number many hundreds, and fresh dis- 

 coveries are frequently announced. Ceres, the 

 first and largest, was discovered January 1, 

 1801, and within three years three others, 

 \\hidi were named Pallas, Juno and Vesta, 

 were seen. 



xtraordmary sm illness of these bodies 



and their nearness to one another gave rise 

 to the erroneous opinion that they are but the 

 fragments of a planet that had formerly ex- 

 isted and had been brought to an end by some 

 catastrophe. For nearly forty years investi- 

 gations were carried on, but no more planets 

 were discovered till December 8, 1845, when a 

 fifth planetoid (Astraea) was found in the same 

 region. The asteroids are now considered to 

 be parts of a ring, similar to the rings of 

 Saturn, broken into minute portions by the 

 attraction or disturbance caused by Jupiter. 

 Eros, one of the smallest, discovered in 1898, 

 approaches the earth more nearly than any 

 other body except the moon. The mean dis- 

 tances of the asteroids from the sun vary be- 

 tween 135,000,000 and 300,000,000 miles, though 

 there may yet be undiscovered ones at far 

 greater distance. The periods of revolution 

 vary between 643 days for Ceres and more 

 than 3,000 days for the most remote. Their 

 total mass does not exceed one-fourth that of 

 the earth. For location, see charts in article 

 ASTRONOMY. 



ASTHMA, az' mah, a distressing malady 

 connected with the process of breathing. The 

 characteristic symptoms of an attack of asthma 

 are difficult breathing, wheezing, coughing and, 

 in extreme cases, slight asphyxia. Asthma is 

 thought to be due to spasm of the minute 

 muscles in the walls of the bronchi. It very 

 often is an accompaniment of hay fever, and 

 attacks may be brought on by inhalation of 

 pollen, as in the latter disease. Some victims 

 are affected by particular odors, and suffer a 

 paroxysm when brought in contact with one 

 of them. Attacks usually begin suddenly, with 

 a preliminary feeling of oppression. They are 

 liable to be worse at night, and are especially 

 bad in a damp, close atmosphere. Storms are 

 often responsible for attacks. The paroxysms 

 recur at irregular intervals and generally pass 

 away in a few hours, though the duration is 

 subject to considerable variation. The patient, 

 in his efforts to obtain air, may grow purple 

 in the face, and his eyes may become blood- 

 shot. 



Men seem to be subject to asthma oftener 

 than women, and a highly-nervous tempera- 

 inrnt predisposes one to the disease. Children 

 often become asthmatic after attacks of 

 measles, bronchitis and whooping cough. 

 Change of climate has been known to arrest 

 tin- disease, which tends to become chronic 

 r a long period of recurring attacks. Drugs 

 are usually of little avail, the best treatment 



