Air, the atmosphere, as opposed to the ether, or higher and purer region (Acts 22:23; 1 Thessalonians 4:17; Revelation 2:2; Revelation 16:17). The phrase to speak into the air (1 Corinthians 14:9) is a proverbial expression to denote speaking in vain, and to beat the air (1 Corinthians 9:26), denotes acting in vain, and is a proverbial allusion to an abortive stroke into the air in pugilistic contests. The later Jews, in common with the Gentiles, especially the Pythagoreans, believed the air to be peopled with spirits, under the government of a chief, who there held his seat of empire. These spirits were supposed to be powerful, but malignant, and to incite men to evil. The early Christian fathers entertained the same belief, which has indeed come down to our own times.