INDEX. 



Defagulicrs, Dr. 314. 



De SauflTure's hygrometer Inaccurate, 17 



Defcotils, 76, 117 



Deyeux, 30 



Dip of the horizon is rendered very uncer- 

 tain by refradlion, 62 — Beft method of 

 afcertaining it at fen, ib. 



Dobfon, Mr, 37 



Dolland, Mr. 144 



Drought, figns of, 155 



Dry-rot, obfervations and communications 

 on, 315— Cure for, 317 



Dudley, Mr. 274 



Dyckhoff, on the aftlvity of a galvanic 

 pile Li which thin ftrata of air are fub- 

 ftituted for wet bodies, 305 



E. 



Earth, the meafure of a degree of, in Lap- 

 land, 76— Its figure and magnitude not 

 fatisfaftorily determined, 102 — Caufes 

 of the errors, 103 — Inveftigation of the 

 formula for computing, 104— Appli- 

 cation of the formulae, 107 — Probabi- 

 lity that it will be determined, 108— 

 Utility of extenfive furveys, 109 



Eckhardt, Mr. G. the inventor of the 

 compound barrel and winch, 50, 267 



Edelcrantz, Sir A. N. his defcription of 

 an apparatus for fuppiying worm-tubs 

 with water, 81— On a fteam dlgefter 

 for philofophical refearches, 161 — De- 

 fcription of his mercurial air-pump, of 

 unlimited exhaufting power, 188 



Efflorefcence and decompofition of glafs 

 tubes, 306 



Eleftricity of the galvanic pile, pheno- 

 mena of, 288 — Method of rendering it 

 very evident, 303 — Molfture not ne- 

 ceflary to its produdion, 305 



flliott's, Mr. new and fimple repeating 

 movement for clocks and watches, 157 



Emerfon, Mr. 292 



fnglefield, SirH. C. on fome remarkable 

 (Irata of flint in a chalkpit in the Ifle of 



\ 



Wight, 183 — Account of the occulta- 

 tion of a fixed ftar by Mars, 198 — Ad- 

 ditional obfervations on the ftrata of 

 flint in the Ifle of Wight, 242 



Erman, Mr. 288 



Eflential oils, method of reftoring whea 

 rancid, 68 



Ether, experiments on the evaporation of, 

 II — Its utility in purifying rancid ef- 

 fential oils, 68 



Evaporation, definition and theories of, 

 5 — Of water, is proportional to the force 

 of vapour at fimilar temperatures, 8— 

 Table of, 10 — Of fpirits, ether, &c. 

 follows the fame laws as water, 13— 

 Of mercury, &c. 15 — Is the fame be- 

 low the point of congelation as above it, 

 ib.— De SauflTure's theory of, 16 



Explofions of diff^erent fulminating pow- 

 ders, method of comparing, 77 



F. 



Fabroni, 34 



Farcy, Mr. on the fiery meteor of Nov. 

 13, and on other fubjedls, 65 



Fafcination by rattle-fnakes and other fer- 

 pents, memoir on, 270— Defcription 

 of the fuppofed procefs, 272— Is denied 

 by the Indians, 274^— Examination of 

 the opinions refpedling, 283 



Ferment, or fermenting principle, opi- 

 nions refpedting, 34 — Experiments to 

 difcover, 35 — Is of an animal nature, 

 36 — Is analogous to the Yeaft of beer, 

 37 — Chemical properties of, 39— -The- 

 ory of its aftion, 42 



Fermentation, vinous, memoir on, 33— 

 Segiiin's theory of, 43 



Fixation of volatile bodies, inftances of, 



lOI 



Fixed ftar, occultation of one by the pla- 

 net Mars, 198 



Flaugergue, 203 



Fleming's, Mr. experiments on the co- 

 louring properties of chay root, 295 



Flints, obfervations on fome remarkable 

 b 2 Arata 



