ABSTRACT
The nature of a fluid so important, should certainly engage the attention of every rational being; for no substance has a more universal influence on the general course of nature. The varieties in it’s temperature and weight are continually agitating our frame; to the action of the changes on bodies the peoples may attribute many of sensations, both irksome and pleasant. Otto de Guericke, an ingenious magistrate of Hamburgh, invented the air-pump in 1654, and made the first public trial thereof about the same time at Ratisbon, before the emperor of Germany, and several of the electors, who were highly delighted with the curious experiments exhibited by it. Artists are accustomed to judge of the goodness of the vacuum in barometers, by the smartness of the found made by the quicksilver.
