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Show BO 0 KS PUBL ISHED BY The Botanic Society at L ichfield. THE SYSTEM OF VEGETABLES, TR A NSLATED FROM THE srsrEMA VEGETABILIUM OF L INNEUS, T wo Volumes, OB:avo. Sold by LEIG!l and So'l'HEBr, Tor k S treet ' Co7.~ent Garde11. EIGHTEEN SHILLINGS IN BOARDS. THE FAMILIES OF PLANTS, TRANSLATED FRDM T HE GENERA PLANTARUM OF LINNEUS, T wo Volumes, OB:avo. Sold by J. JoHNSON, St. Paul's Cbnrch - Yard. SIXTEEN SHILLINGS lN BOARDS. ADDITIONAL NOTES. NOTE I.--METEORS. E thereal Po'Wers I you chafe the ./hootingfiars. Or yoke the vollied lightnings to your cars. T H E R E feem to be thr<e cone<n t'ic fiuta of ou, incumbent atmofphece ; in which, or between them, are produced four kinds of meteors ; lightning, lhootiog il:ars, fire-balls, and northern lights. Firil:, the lower region of air, or that which is denfe enough to refill: by the adhefion of its particles the defcent of condenfed vapour, or clouds, which may extend frotn one to three or four miles high. In this region the common lightning is produced from the accumulation or defeB: of eleB:ric matter in thofe floating fields of vapour either in refpeB: to each other, or in refpeB: to the earth beneath them, or the diffolved vapour above them, which is conll:antly varying b0th with the change of the form of the clouds, which thus evolve a greater or lefs furface, and alfo with their ever. i::hanging degree of condenfation. As the lightning is thus produced in denfe air, it pro. ceeds but a lhort courfe on account of the greater refifl:ance which it encounters, is attended with a loud explo!ion, and appears with a red light. 2. The fecond region of the atmofphere I fuppofe to be that which has too little tenacity to fupport condenfed vapour or clouds; but which yet contains invifible vapour, or water in aerial folution. This aerial folution of water differs from that diffolved in the matter of heat, as it is fupported by its adhefion to tl:!e particles of air, and is not precipitated by cold. In this fl:ratum it feems probable that the meteors called lhooting ftars are produced ; and that they confifl: of electric fparks, or lightning, paffing from one region to another of thefe invifible fields of aero-aqueous folution. The height of thefe fhootillg fl:ars has not yet been afcertair1ed by fuflici ent obfervation ; Dr. Blagden thinks their fituation is lower down in the atmofphere than that of fireballs, which he conjectures from their fwift apparent motion, and afcribes their fmallnefs to the more minute di,·ifion of the electric matter of which they are fuppofed to w nfiil:, owing t" A |