The well-known favourite "The Mouse's Petition" [...] had its origin from the following circumstance. Dr. Priestley, from the vicinity of his residence to a large brewery had been led to notice the suffocating vapor which is extricated in the process of fermentation (now so well known as the carbonic-acid-gas, but then denominated by Dr. Black, fixed air, and by Dr. Rutherford, mephitic air); and this circumstance, happily for science, further led him to that train of discoveries which gave rise to pneumatic chemistry, and immortalized his name among philosophers. In the midst of these investigations Miss Aikin found him.—[...] In the course of these investigations, the suffocating nature of various gases required to be determined, and no more easy or unexceptionable way of making such experiments could be devised, than the reserving of these little victims of domestic economy, which were thus at least as easily and as speedily put out of existence, as by any of the more usual modes. It happened that a captive was brought in after supper, too late for any experiment to be made with it that night, and the servant was desired to set it by till the next morning. Next morning it was brought in after breakfast, with its petition twisted among the wires of its cage. It scarcely need be added, that the petition was successful.