AI'RAY, HENRY, D.D., d. 1616; a Puritan preacher, and president of Queen's col lege, Oxford. When first a student he was poor, and did servile work in the college ; but he rose in station, took orders, and became a frequent and zealous preacher, a thorough Calvinist and a fiery opponent of Romanism. In 1606 be was vice-chancel lor of the university, and was also rector of Otmoor. He was a good specimen of the more cultured Puritans.
and AIR-CUSHIONS. Air-beds were known as early as the beginning of the 18th c., but being made of leather, were expensive. It was only after the invention of air-tight or Macintosh cloth that it became possible to use air in this way at a moderate cost. An air-bed consists of a sack in the form of a mattress, divided into a number of compartments, each air-tight • a projection at one end forms a bolster. Each compartment has a valve, through which the air is blown in by bellows. The advan tages of such beds, in point of cleanness, coolness, lightness and elasticity are obvious. They are specially valuable in many cases of sickness. The is another contrivance of the same kind. Recently, vulcanized India-rubber, instead of cloth, has been used in the fabrication of such articles. The chief drawback to these contrivances is the liability to being spoiled by a rent or other injury.
or SWIMMING-BLADDER, in fishes. An organ apparently intended to aid them in ascending in deep water, and for the accommodation of their specific gravity to various depths. It is made to serve this purpose by the increase or diminution of its volume, according to the degree of pressure exerted upon it by the ribs. Its place is in the abdomen, limier the spine ; and it is very various in size and form in different kinds of fishes. It generally has an opening into the oesophagus, or into the stomach, but appar ently only for the ejection and not for the admission of air. In some fishes it has no a -opening. The air with which the A. is filled c Aappears to be the result of secretion; and in fresh • ':- . • water fishes consists in general almost entirely of
• - .., - nitrogen, but contains a larger proportion of oxy ti --- . E gen in sea-fishes, the oxygen in deep-sea fishes having been found to amount to 87 per cent.
Air-bladder of carp: consisting of two The A. is in some fishes very small; in others, it parta—B and C, joined a narrow neck; A D, a canal communicating with is entirely wanting, particularly in fishes that are ceophagus, E. destined to live chiefly at the bottom of the water, as flat fishes, eels, etc. ; but there are remarkable instances of AS absence also in species of very different habits, such as the common mackerel, whilst it exists in other species of the same genus or family. The A. of fishes affords the finest-kind of isinglass.
or Ant-SAcs, in birds, are remarkable cavities connected with the piratory system. They are distributed along the inside of the ..
whole cavity of the chest and abdomen; and in birds of strong wing and rapid flight, often send prolongations into the bones.,_..- , They are connected with the extremely active respiratory sys- o'•- .fr-_.z„`,1.3 .'; \.:,.„ ......b tea, and communicate with the lungs, giving an immense :. .
• a -:. „ Al iii. ! extension to the surface with which the air inhaled comes ini . ' :, contact. • '..e.; ty v .! .(1 tit j t• .• a ,:.) The cells in the lungs of the nianimalia into which the air 1 is conveyed by minute ramifications of the windpipe, in ., order to be brought into contact with the blood distrib .; , uted on their walls are very small; in man, , om ..*Pk ,,,..: s only about one hundredth part of an inch in -',,•., ., . / diameter.—Air-cells, or air-sacs, may be said ) . . ?, to form the whole respiratory apparatus in * .
some of the lower kinds of animals (see e ,-er : .
'Atit; ' .. a.