INDEX. 



the quantity of water carried off by ri- 

 ver's and by evaporation, 159.— On the 

 origin of fprings, 172, 221 



Darracq on the affinities of earths, 17 



Davy, Mr. his method of eftimating the 

 changes of volume in gas during chemi- 

 cal experiments, 32. — On the appear- 

 ances produced by the collifion of fteel 

 with hard bodies, 103 



Decandolle, Cit. 254 



Declivities of mountains, on the, 256 



Decompofition of thought, queftion on, 

 279 



Delarive on the found produced in tubes 

 by hidrogen gas, 23 



De Luc, 34, 265 



De SaulTure, 206 



De formes, 34 



Dew, Mr. Dalton's experiments and ob- 

 fervations on, 159. — Quantity of, 162 



Difoxigenating tays of light, 100 



Difperfive powers, method of examin- 

 ing by priimatic reflection, 89. — Of 

 various bodies, 95. — Of the eye, 187 



Diffemination of plants, on the, 253 



Diftances, formula for calculating, 118.— 

 How found from the magnitude of the 

 object, 119 



Dobfon, Dr. 167 



Dollond, Mr. 97, no 



Dolomieu, 264 



Dormice, queftion refpecting, 278 



Dortharen, Baron de, his excurfion to the 

 fummit of Mont Blanc, 206 



Drops, Englifh, 271 



Earths, affinities of for each other, 16. 

 —Guy ton's experiments, ib.— Con- 

 tefted by Darracq, 17.— The earth 

 twice univerfally covered with water, 

 261 



Electricity of wood fhavings, 49— -Re- 

 fraction of the light of, 100 



Emery, the compofition of, 53.— -Re- 

 fembles corundum, 5$. — Hardnefs of, 

 ib. 



Engine for raifing and lowering weights hj 

 water, 44.— May be ufed as a crane, 

 45.— Not affected by fioft, 47 



England and Wales, annual quantities of 

 rain and dew fallen in, 160.— Area of, 

 163 



Eflential oils, foluble in acetic acid, 215 



Evaporation, quantity of water raifed by, 



X59 Method of eftimating, 167.— 



At high temperatures, experiment^ on, 

 207 



Evelyn, Sir G. S. 35 



Euler, no 



Eye, the difperfive powers of, 187 



Faculties, internal, the brain is the organ 

 of the, 198.— Their energy not in pro- 

 portion to the volume of the brain, 199 

 Fecula, green, of plants, 273.— Charac- 

 ters of, 277 

 Felfpar, component parts of, 13, 14 

 Fermentation, peculiar, ofcheefe, 276 

 Fibrohte, component parts of, 13, 14 

 Finery cinder contains wateronly, but not 



oxigen, 66 

 Fire occasioned by oxidule of phofphorus, 



217 

 Fit« -James, account of ventriloquifm as 



exhibited by, 202 

 Fixed air not decompofed by iron, 67 

 Flalh from an air-gun, 280 

 Fletcher, Mr. his tfbfervations on the 

 ftandard of weight and meafure, 35, 

 280 

 Fluids, on their power as conductors of 



heat, 56. — Internal motion of, 75 

 Fly -carrier, defcription of the infect, 266 

 Food, organ of the choice of> 202 

 Forfait, Cit. 246 

 Formic acid is compofed of the malic and 



acetous acids, 2^4 

 Forneret, M. his excurfion to the fummit 



of Mont Blanc, 206 

 Forfter, 254 

 Fofter, J. R. 259 



Fourcroy, 129, 133, 273. — Accufe* the 

 b 2 ancient 



